grsecurity

All affected users must patch against php2shell (CVE-2026-109618 / CVE-2026-109619). Due to the nature of some of the primitives involved, ASLR is not effective and arbitrary code execution/reuse/filesystem-level execution isn't a necessary component of exploitation in this case.

KERNSEAL makes the linear page cache overflow in cyberstan.co.uk/fuse-readdir... deterministically unexploitable. Serial log below 👇

We've just published a Knowledge Base article with more information about the vulnerability, current published/unpublished exploits, and current mitigations. We still recommend patching ASAP.

We've just sent a mail to all customers notifying them of this issue, with split-out fixes available for 5.15, 6.6, and 6.18. We'll share more information on our Knowledge Base as it becomes available.

We've published a detailed KB article for customers on the two vulnerabilities involved in Dirty Frag and the associated public exploits, feel free to reach out with any questions.

The KB article with links to the combined/split-out patches for 5.15 and 6.6 (adapted to grsecurity) are now available.

Updated 5.15 and 6.6 patches are now available. We're now preparing a KB article with more guidance than shared in last night's email with links to combined/split-out patches for both 5.15 and 6.6 for those on older kernels who need CONFIG_CRYPTO_USER_API_AEAD enabled (which shouldn't be anyone)

Our 6.18 #grsecurity LTS release, to be supported through at least the end of 2028, is now available!

Just sent out our year end wrap-up mail to customers. It's a bit bigger than usual, so grab yourself some Swiss Miss and enjoy! If you didn't receive it, but should have, just reach out and we'll make sure you're on the list. Happy holidays!

6.18 has been selected as the next #grsecurity stable kernel version, to be supported through the end of 2028, one year longer than the upstream LTS EOL date of Dec 2027.

Quick reminder that our 6.8 short-term stable kernel goes EOL at the end of this month. Some stats: over the period of a year, it included over 1500 security/stability-relevant backports.

Nice demo: tested a vulnerable Ubuntu 22.04 system for glibc CVE-2025-4802 using Solar Designer's PoC adapted to Ubuntu (replace any occurrence of "myhostname" with "mdns4_minimal"). Even an old #grsecurity 5.4.96 kernel from February 8 2021 prevented exploitation

It's now available!

We expect our 6.13 #grsecurity beta to be available within the next two weeks.

github.com/google/secur...

Our 6.12 #grsecurity beta is now available to beta testers for testing

Slides for Pawel's H2HC presentation this month on the TLB are now available on grsecurity.net/papers If you've never heard of "paging-structure caches" before, check it out!

We need to post a correction to yesterday's eBPF performance numbers: Mathias Krause wasn't happy with just a 30x speedup and took a look at one final bottleneck that was bothering him. The speedup over vanilla is now 747x 🤯 (5.27s vs 1h5m40s)

Johannes Wikner has published a detailed walkthrough of the first cross-process Spectre exploit against a real target, an attack he developed in part during his internship with us last year. Check it out here: grsecurity.net/cross_proces...

A new version of paxctld (1.2.6) is now available for download!