A use-after-free vulnerability in the Linux kernel bridge (net/bridge) Spanning Tree Protocol (STP) implementation.

A bridge that is administratively down while kernel STP is enabled, together with a port driven into the LEARNING state, arms periodic STP timers without an IFF_UP guard.

The teardown path taken by dellink never synchronously deletes those timers, so the backing net_device (which embeds struct net bridge as private data) is freed with a timer list still queued on a per-CPU timer base.

The result is a slab use-after-free in the kmalloc-cg-8k cache.

Hi. I just published a four-part deep dive into windows kernel exploitation, progressing from classic control flow hijacking to modern pool grooming and pure data-only attacks on windows 11.

I wanted to highlight the real-world friction of modern security measures. A lot of the focus is on mitigating LFH randomization, and avoiding IoCompleteRequest bugchecks by dodging ReadFile for arbitrary reads.

Hope this is helpful or insightful to some of you looking into modern kernel exploitation.

Questions regarding netsec and discussion related directly to netsec are welcome here, as is sharing tool links.

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In three incidents across six runs, the agents treated real systems as simulated targets and tried weak passwords or unauthenticated endpoints.

When a compromised AI Agent holds valid credentials (such as OAuth tokens or DB keys), traditional perimeter defenses like WAFs, EDRs, and LLM prompt firewalls often become ineffective.

Recently, I've been researching a approach to bring runtime governance down to the C-ABI (Application Binary Interface) system call layer to enforce deterministic execution boundaries for local agentic workflows.

Key Architectural Considerations I'm testing:
- Deterministic Binary Gate: Pre-compiled permissions mapped to immutable O(1) bitmaps, causing illegal syscalls to physically fail with <500ns panic latency.
- Cryptographic Identity Binding: A 3-Tier PKI Certificate Authority architecture coupled with identity tokens (DIT) to resolve OS-level execution context loss.
- B2B Multi-Enterprise Supply Chain Defense: Simulating agentic supply chain execution vectors (e.g., automated workload interactions with untrusted external repos).

I'd love to hear feedback from the netsec community on deterministic runtime bounds and sandbox isolation models for autonomous agents. Is pushing governance down to the C-ABI layer practical in your agentic environments, or are there edge cases in execution context tracking that I might be overlooking?

Active Storage's default vips variant processor exposes an arbitrary file read that chains to RCE on stock Rails 7.x and 8.x, where the app serves back processed variants of user-supplied images. No authentication required in certain setups. Only vips is affected, Magick is not.

Patched in 7.2.3.2, 8.0.5.1, and 8.1.3.1, and the fix requires libvips 8.13+. Chain and PoC withheld while patches roll out.