CVE-2026-74579: Linux kernel · netfilter: nft_payload: fix mask build for partial field offload
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.1 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +28
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 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 should be applied to affected Linux kernel versions. The vendor advisory from Ubuntu confirms that this issue has been fixed. Users should update their Linux kernel packages to the fixed versions to remediate this vulnerability.
Description
A vulnerability in the Linux kernel's netfilter nft_payload component was fixed. The issue involved incorrect mask building for partial field offload in nft_payload_offload_mask(), causing undefined behavior due to an out-of-bounds bit shift on 32-bit integers and over-masking of bytes. This could lead to incorrect packet matching behavior. The vulnerability has been addressed by correcting the mask construction logic to avoid undefined shifts and over-masking.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74579 (opens in a new tab)
- git.kernel.org/stable/c/16b553c46e347bc9de9946c4960654d5884a86de (opens in a new tab)
- git.kernel.org/stable/c/363c3a84a946d53e5e121c9f47c7c2b7d228c46b (opens in a new tab)
- git.kernel.org/stable/c/39e88f28fb32bf02bd4b525c24c842c9cff5663d (opens in a new tab)
- git.kernel.org/stable/c/3ee7b3f813b11f28cd6efdf7f24d64b5a7fd4dc7 (opens in a new tab)
- git.kernel.org/stable/c/630295d5bba1d0e0f494cc459452eb0a0058c545 (opens in a new tab)
- git.kernel.org/stable/c/8720df4504e0ed1781a702f65251bd47b3534d5e (opens in a new tab)
- git.kernel.org/stable/c/a375d8ace807767f29f276b681b6324c74929b1d (opens in a new tab)
- git.kernel.org/stable/c/b19b5d2e042c294e2cc1c908dc598f9d64015396 (opens in a new tab)
- ubuntu.com/security/CVE-2026-74579 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74579 (opens in a new tab)
- git.kernel.org/linus/39e88f28fb32bf02bd4b525c24c842c9cff5663d (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-2 (opens in a new tab)