CVE-2025-40169: Linux kernel · bpf: Reject negative offsets for ALU ops
Source GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Nov 2025
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
AI-suggested
A fix has been implemented in the Linux kernel to correct the offset validation logic in the BPF verifier. Users should update their Linux kernel to a version that includes this fix. Since this is a kernel vulnerability, patching the kernel is the recommended remediation. No alternative mitigations are indicated.
Description
A vulnerability in the Linux kernel's BPF verifier allowed negative offsets in ALU operation instructions due to improper validation of the signed 16-bit offset field. This flaw permitted malformed BPF programs with offsets other than the explicitly allowed 0 or 1, potentially leading to high impact on confidentiality, integrity, and availability. The issue has been resolved by tightening the validation logic to reject any offset values other than 0 and 1.
References
- nvd.nist.gov/vuln/detail/CVE-2025-40169 (opens in a new tab)
- git.kernel.org/stable/c/21167bf70dbe400563e189ac632258d35eda38b5 (opens in a new tab)
- git.kernel.org/stable/c/3bce44b344040e5eef3d64d38b157c15304c0aab (opens in a new tab)
- git.kernel.org/stable/c/5017c302ca4b2a45149ad64e058fa2d5623c068f (opens in a new tab)
- git.kernel.org/stable/c/55c0ced59fe17dee34e9dfd5f7be63cbab207758 (opens in a new tab)