CVE-2026-74433: Linux kernel · rxrpc: Fix UAF in rxgk_issue_challenge()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 7.0.0-1013.13~24.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1013.13~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +12
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and has been released by Ubuntu in security advisory USN-8816-1. Users should update their Linux kernel to the fixed versions and reboot their systems to apply the changes. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be necessary. Follow vendor instructions for updating and rebuilding modules as needed.
Description
A use-after-free (UAF) vulnerability in the Linux kernel's rxrpc subsystem was fixed in the function rxgk_issue_challenge(). The flaw involved improper freeing of memory containing challenge content after a tracepoint invocation, which could lead to memory corruption. This vulnerability affects multiple specific Linux kernel versions and has a high CVSS score of 9.8. Ubuntu has released patches addressing this and other kernel security issues. Users should update and reboot to apply the fixes.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74433 (opens in a new tab)
- git.kernel.org/stable/c/107a4cb0d47e735830f852d83970d5c81f8e1e08 (opens in a new tab)
- git.kernel.org/stable/c/83bb0ed050e2ad9453d8ef50e4d6e624eac6eed8 (opens in a new tab)
- git.kernel.org/stable/c/844b8525ce503405c462ad67f750bec648720397 (opens in a new tab)
- ubuntu.com/security/CVE-2026-74433 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74433 (opens in a new tab)
- git.kernel.org/linus/107a4cb0d47e735830f852d83970d5c81f8e1e08 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)