High · CVSS 7.8CVE-2025-40169

bpf: Reject negative offsets for ALU opsCVE-2025-40169

Answer in brief

CVE-2025-40169 records a High severity (CVSS 7.8) vulnerability in bpf: Reject negative offsets for ALU ops. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Nov 12, 2025Updated Oct 19, 2026Source checked Nov 4, 2026First seen by HOL Aug 5, 2026Material review Oct 19, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.8
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=ec0e2da95f72d4a46050a4d994e4fe471474fd80 <3bce44b344040e5eef3d64d38b157c15304c0aab \|\| >=ec0e2da95f72d4a46050a4d994e4fe471474fd80 <5017c302ca4b2a45149ad64e058fa2d5623c068f \|\| >=ec0e2da95f72d4a46050a4d994e4fe471474fd80 <21167bf70dbe400563e189ac632258d35eda38b5 \|\| >=ec0e2da95f72d4a46050a4d994e4fe471474fd80 <55c0ced59fe17dee34e9dfd5f7be63cbab207758	3bce44b344040e5eef3d64d38b157c15304c0aab, 5017c302ca4b2a45149ad64e058fa2d5623c068f, 21167bf70dbe400563e189ac632258d35eda38b5, 55c0ced59fe17dee34e9dfd5f7be63cbab207758
Linux/Linuxgeneric	6.6	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 3bce44b344040e5eef3d64d38b157c15304c0aab if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Nov 12, 2025
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject negative offsets for ALU ops When verifying BPF programs, the check_alu_op() function validates instructions with ALU operations. The 'offset' field in these instructions is a signed 16-bit integer. The existing check 'insn->off > 1' was intended to ensure the offset is either 0, or 1 for BPF_MOD/BPF_DIV. However, because 'insn->off' is signed, this check incorrectly accepts all negative values (e.g., -1). This commit tightens the validation by changing the condition to '(insn->off != 0 && insn->off != 1)'. This ensures that any value other than the explicitly permitted 0 and 1 is rejected, hardening the verifier against malformed BPF programs.

Quoted source text, attributed separately from HOL analysis.