cURL developer Daniel Stenberg has seen Anthropic’s Mythos, a model the AI biz has suggested is too capable at finding security holes to release publicly, scan his popular open source project. But after the system turned up just a single vulnerability, he concluded the hype around Mythos was “primarily marketing” rather than a major AI security breakthrough. Stenberg explained in a Monday blog post that he was promised access to Anthropic’s Mythos model - sort of - through the AI biz’s Project Glasswing program. Part of Glasswing involves giving high-profile open source projects access via the Linux Foundation, but while Stenberg signed up to try Mythos, he said he never actually received direct access to the model. Instead, someone else with access ran Mythos against curl’s codebase and later sent him a report. “It’s not that I would have a lot of time to explore lots of different prompts and doing deep dive adventures anyway,” Stenberg explained. “Getting the tool to generate a first proper scan and analysis would be great, whoever did it.” That scan, which analyzed curl’s git repository at a recent master-branch commit, was sent back to him earlier this month, and it found just five things that it claimed were “confirmed security vulnerabilities” in cURL. Saying he had expected an extensive list of vulnerabilities, Stenberg wrote that the report “felt like nothing,” and that feeling was further validated by a review of Mythos’ findings. “Once my curl security team fellows and I had poked on this short list for a number of hours and dug into the details, we had trimmed the list down and were left with one confirmed vulnerability,” Stenberg said, bringing us back to the aforementioned number. As for the other four, three turned out to be false positives that pointed out cURL shortcomings already noted in API documentation, while the team deemed the fourth to be just a simple bug. “The single confirmed vulnerability is going to end up a severity low CVE planned to get published in sync with our pending next curl release 8.21.0 in late June,” the cURL meister noted. “The flaw is not going to make anyone grasp for breath.” That said, Mythos did find several other non-security bugs that Stenberg said the team is working on fixing, and he notes that their description and explanation were well done. Mythos can do good work, in other words, but it’s not a ground-breaking, game-changing AI model like Anthropic has claimed. “My personal conclusion can however not end up with anything else than that the big hype around this model so far was primarily marketing,” Stenberg said in the blog post. “I see no evidence that this setup finds issues to any particular higher or more advanced degree than the other tools have done before Mythos.” cURL code is no stranger to AI To say cURL has become widely used in its nearly three decades of existence would be an understatement. Its wide reach has meant that its team has been running it through all sorts of static code analyzers and fuzz testing it since well before the dawn of the AI age. With AI’s rise, the cURL team has adapted, meaning Mythos is hardly the first AI to get its fingers on cURL’s codebase. “These tools and the analyses they have done have triggered somewhere between two and three hundred bugfixes merged in curl through-out the recent 8-10 months or so,” Stenberg said of tools like AISLE, Zeropath, and OpenAI Codex Security that’ve tested cURL code. “A bunch of the findings these AI tools reported were confirmed vulnerabilities and have been published as CVEs. Probably a dozen or more.” Stenberg’s experience with AI testing cURL, in other words, makes it a great candidate to see how effective Mythos can really be at finding more than the average AI. As Stenberg noted elsewhere in his blog post, Mythos isn’t doing anything particularly novel when it comes to security discoveries: It might be a bit better at finding things than previous models, but “it is not better to a degree that seems to make a significant dent in code analyzing,” the cURL author noted. Stenberg isn’t an AI doomer when it comes to its ability to improve software design, though. Yes, he may have closed the cURL bug bounty earlier this year due to an influx of sloppy, useless bug reports, but he also noted a few months prior to the bounty closure that some security researchers assisted by AI have made valuable reports. “AI powered code analyzers are significantly better at finding security flaws and mistakes in source code than any traditional code analyzers did in the past,” Stenberg said, adding an important qualifier for the Mythos moment: “All modern AI models are good at this now.” Mythos isn’t any more creative than its creators Both older AI models and security-focused tools like Mythos have a common limitation, as far as Stenberg is concerned: They’re only as good at finding security vulnerabilities as the humans who programmed them. “AI tools find the usual and established kind of errors we already know about. It just finds new instances of them,” Stenberg said. “We have not seen any AI so far report a vulnerability that would somehow be of a novel kind or something totally new.” As for Mythos, Stenberg remains unimpressed, calling it "an amazingly successful marketing stunt for sure" in his blog post. In an email to The Register, Stenberg admitted that it’d be possible for AI models to actually discover new, novel types of vulnerabilities, but he’s still not convinced that they can go beyond what humans are capable of finding, given that they’re limited by our understanding of how software vulnerabilities work. At the end of the day, Stenberg explained, when we talk about security, we’re only talking about code. “Source code is text and it feels like maybe we already know about most ways we can do security problems in it,” he pondered in his email. In other words, like the valuable AI-assisted reports made to the cURL bug bounty program before its closure due to a flood of AI garbage, making valuable use of systems like Mythos is going to require humans to get creative. Sorry, no foisting your critical thinking onto a bot. “Human researchers have always used tools when they look for security problems,” Stenberg told us. “Adding AIs to the mix gives the humans even more powerful tools to use, more ways to find problems. I expect that many security bugs going forward will be found by humans coming up with new ways and angles of prompting the AIs.” Stenberg said that he hopes he’ll actually get his hands on Mythos so he can experiment with its capabilities, but he doesn’t seem to be holding out hope the promised access will materialize. “I have been promised access and for all I know I will eventually get it,” Stenberg told us. “I just don't know when.” ®

BWH Hotels is informing customers about a third-party data breach that gave cybercriminals access to six months' worth of data. The notification email stated that BWH Hotels, which owns the WorldHotels, Best Western Hotels & Resorts, and Sure Hotels brands, identified the intrusion on April 22, but the affected data goes back to October 14, 2025. BWH Hotels CTO Bill Ryan, who penned the notification email, said names, email addresses, telephone numbers, and/or home addresses belonging to "certain guests" were accessed by an unauthorized third party. The intruders also accessed reservation details, such as reservation numbers, dates of stay, and any special requests. It confirmed that the attack targeted one of its "web applications that houses certain guest reservation data." No payment or bank details were involved. The Register asked BWH Hotels whether the intrusion began in October and went undetected until April, or whether a later breach exposed data dating back to October. We also asked if this was related to information we were sent in March about BWH Hotel customer booking data being stolen and used for phishing campaigns. At the time, the company neither confirmed nor denied the information seen by The Register. BWH Hotels did not immediately respond to our request for comment on Monday. "Upon discovering the incident, we immediately took the application offline and revoked the unauthorized access," said Ryan. "We have engaged leading external cybersecurity experts to support our incident response efforts and to assist with the further strengthening of existing safeguards." "We advise guests to be extra vigilant when viewing any unexpected or suspicious communications about hotel stays. If you receive a suspicious communication such as an unexpected email, text, WhatsApp message, or telephone call that asks for payment, codes, logins, or 'verification,' even if they reference a BWH Hotels property or an upcoming reservation, do not engage. Navigate to sites directly rather than clicking links." ®

Checkmarx’s software engineers are still working to remove a malicious version of the code security outfit's Jenkins plugin after detecting an unauthorized upload over the weekend. It updated customers on Saturday, May 9, after discovering a version of its AST Scanner, which is used for security scans in Jenkins CI pipelines, was made available via the Jenkins Marketplace. “We are aware that a modified version of the Checkmarx Jenkins AST plugin was published to the Jenkins Marketplace,” it said in a statement. “We are in the process of publishing a new version of this plug-in.” Versions published as of May 9, 2026, should not be trusted, it added, before urging all users to check they’re running the correct release (2.0.13-829.vc72453fa_1c16) published on December 17, 2025. Installed by several hundred controllers, the plugin remains available at the time of writing, and appears as the most recently available version, although pull requests actioned on Monday morning suggest this will soon be pulled down. “What makes this particularly dangerous for Jenkins users is the trust model at play,” said SOCRadar in its coverage. “The Checkmarx Jenkins plugin is a tool people install specifically to improve the security of their pipelines. “A backdoored version doesn’t just compromise one project; it rides trusted infrastructure into every build pipeline it touches, with access to source code, environment variables, tokens, and whatever secrets the runner can see.” Security engineer Adnan Khan spotted the compromise quickly over the weekend. The crew behind the early supply chain attack affecting Checkmarx in April, TeamPCP, defaced the company’s GitHub and published six packages, each with a description alluding to the Shai-Hulud wormable malware. These packages no longer appear on Checkmarx’s GitHub, but TeamPCP made multiple changes to the AST plugins page, renaming it to “Checkmarx-Fully-Hacked-by-TeamPCP-and-Their-Customers-Should-Cancel-Now,” and altering the description to claim CheckMarx failed to rotate its secrets. The latest infiltration of Checkmarx’s internals marks the third time TeamPCP has compromised the company’s packages in as many months. As previously seen in The Register, the crooks successfully targeted Checkmarx’s AST plugin for GitHub Actions and its KICS static analysis tool back in March, deploying credential-stealing malware. SOCRadar said the latest TeamPCP compromise of the Jenkins plugin suggests that either TeamPCP was telling the truth about Checkmarx’s secrets rotation, or its members took advantage of an additional persistence mechanism that the security vendor failed to notice during its response to the March intrusion. ®

OPINION There are three little words to make the heart beat faster in anyone who knows what they mean: critical infrastructure resilience. If you run that infrastructure or a country dependent on it, you need energy, communication and transport to be impregnable to cyber attacks. This is doubly so if that country is five minutes by incoming missile from an implacable hyper-competent enemy sworn to invade you. One that is building and equipping its military as fast as it can with this one thing in mind. One with the most invasive and brazen state hacking machinery on the planet. Thus it was a very bad day indeed when Taiwan’s entire bullet train system was disabled for nearly an hour by an unknown attacker. It got even worse when that attacker turned out not to be the implacable and hyper-resourced state actor over the Taiwan Strait, but a university student with a yen for radio and some kit he bought online. On the one hand, it’s good to see the good repair of the grand tradition of young hackers causing havoc from their bedrooms. On the other, WTRF? The information released by the Taiwanese authorities is scant on details, but enough to be pretty sure what actually happened. It’s bad news not just for Taiwan but for more than 100 countries that also use the TETRA two-way radio standard involved, often for emergency services. In many cases, it was the default replacement for unencrypted FM two-way radios, adding encryption, flexibility and network security. These were state of the art when TETRA was developed in the 1980s and 1990s — and work as well in 2026 as you might expect. Oops. There have been upgrades and, especially after the 2023 vulnerability disclosures, an accelerated program of making things better. A lot of the installed base globally is old, lacks over-the-air updates for security, and in any case spending money on new radios is normally at the bottom of the list for any state or public service organizations. Things have to get really bad first. Perhaps they just have. (North America is the only region where TETRA is uncommon, as it isn’t approved for public service use. This was either acute foresight or the fact that the TE in TETRA, now officially TErrestrial, used to stand for Trans-Europe. The American system, P.25, has never, however, been renamed Freedom Frequencies. Now on with the show) The network vulnerabilities are one side of the story. Our doughty hacker is the other. Reportedly, he didn’t have any TETRA hardware, but a laptop connected to a radio and an ‘SDR filter’. The latter makes little sense, it is far more likely that he had a software defined radio (SDR) called a HackRF. There are plenty of other devices that could have been used, but the HackRF is the weapon of choice for the gung-ho radio nut. SDR is a technique that has completely changed the rules of how to radio. All radios before it had to be entirely or mostly analog, with precision hardware dedicated to whatever job each radio had to do. This hardware could also be looked at as an analog computer, as it can be modelled as a set of mathematical transformations on the received signal. Analog computers have their place, just not in the 21st century. SDR is radio as digital computer. At heart, it has three components: an analog to digital converter to turn the incoming signal to a stream of numbers, very fast processing to do the radio math, and a digital to analogue converter to play the results. What you get is triply terrific. Digital processing is perfect, analog processing adds noise and distortion. Nothing is fixed, everything can be re-engineered with new code. And it can be hog-whimperingly cheap. HackRF is all those things and more. It can be configured as a portable touch-screen device. It transmits and receives from DC to daylight. You can pick one up for less than the price of a mid-range mobile. It is open source. It works with all manner of SDR creation tools, utilities and radio packages. There are infinite legitimate uses. Most excitingly, you can download apps for it that do everything, most especially the kind of thing that will introduce you with surprisingly rapidity to a wide range of new friends with no sense of humor and love letters that look suspiciously like arrest warrants. Think of it as speed dating but with more guns and less no thank yous, GPS spoofing, aviation and marine location transponders, satellite comms, data eavesdropping and injection - take your pick. You’ll need it to unlock the cell door. It is the data detection and injection that seems to have been the downfall of all concerned. A handset had its transmission decoded, and the result was retransmitted into the system as if it were that original radio. Whether the decoded data already had the General Alarm set, or whether the data had to be modified before retransmission, is not yet known. Doesn’t matter. It’s called a replay attack, and it has and is mostly used in stand-alone devices called code grabbers to unlock and steal expensive cars with wireless keys. Some countries, including Canada and the UK, have banned code grabbers, but this has failed on two counts. Code grabbers are small gadgets that can be bought online from China, and good luck policing that. Also, thieves are notably indifferent to laws. That notwithstanding, the UK is thinking of extending the ban to other classes of naughty wireless, and would doubtless like to do the same with HackRF, at least as of last week. Of course, they can’t be banned. SDRs can’t be banned as a class, especially open source ones made out of standard chips and open code. They are general purpose computers, albeit with specialisms. It doesn’t matter if you’re dismayed or delighted that things like HackRF exist, that genie is out of the bottle. What is truly dismaying is that replay attacks are a solved problem, trivially so. Choose a big keyspace, randomize and never repeat keys. That one is on lazy car makers and, apparently, the world of TETRA. Fixing that class of lazy, outdated security vulnerability will be very expensive. Embedded systems are like that, especially old ones. Not fixing this will be a gamble with infinite downside, in a world where electronic warfare systems that used to cost hundreds of millions now pour out of Ali Express for a few bucks. HackRF is to Tetra like Crocodile Dundee’s knife is to the mugger’s. Critical infrastructure resilience. Just three little words, but if you say them you better mean it. And it won’t be cheap. ®