ipv4: start using dst_dev_rcu()

Answer in brief

CVE-2025-40074 records a Critical severity (CVSS 9.8) vulnerability in ipv4: start using dst_dev_rcu(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), 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 Oct 28, 2025Updated Sep 14, 2026Source checked Sep 21, 2026First seen by HOL Aug 5, 2026Material review Sep 14, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.8
Exploitation: Not marked as known exploited
Affected software: 4 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 9.8. 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), 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	>=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <923e0734c386984d45de508528a7a7ad91d791cc \|\| >=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <6ad8de3cefdb6ffa6708b21c567df0dbf82c43a8	923e0734c386984d45de508528a7a7ad91d791cc, 6ad8de3cefdb6ffa6708b21c567df0dbf82c43a8
Linux/Linuxgeneric	4.13	Not reported
Linux/Linuxgeneric	>=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <684efb2c86c887685f9aa65e1a21b3df6c1f822d \|\| >=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <923e0734c386984d45de508528a7a7ad91d791cc \|\| >=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <6ad8de3cefdb6ffa6708b21c567df0dbf82c43a8	684efb2c86c887685f9aa65e1a21b3df6c1f822d, 923e0734c386984d45de508528a7a7ad91d791cc, 6ad8de3cefdb6ffa6708b21c567df0dbf82c43a8
Linux/Linuxgeneric	>=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <e150f273cd8ed34ebc6d03758aad95c12fc58337 \|\| >=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <684efb2c86c887685f9aa65e1a21b3df6c1f822d \|\| >=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <923e0734c386984d45de508528a7a7ad91d791cc \|\| >=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <6ad8de3cefdb6ffa6708b21c567df0dbf82c43a8	e150f273cd8ed34ebc6d03758aad95c12fc58337, 684efb2c86c887685f9aa65e1a21b3df6c1f822d, 923e0734c386984d45de508528a7a7ad91d791cc, 6ad8de3cefdb6ffa6708b21c567df0dbf82c43a8

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 923e0734c386984d45de508528a7a7ad91d791cc; Linux/Linux to 684efb2c86c887685f9aa65e1a21b3df6c1f822d; Linux/Linux to e150f273cd8ed34ebc6d03758aad95c12fc58337 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 28, 2025
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 14, 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: ipv4: start using dst_dev_rcu() Change icmpv4_xrlim_allow(), ip_defrag() to prevent possible UAF. Change ipmr_prepare_xmit(), ipmr_queue_fwd_xmit(), ip_mr_output(), ipv4_neigh_lookup() to use lockdep enabled dst_dev_rcu().

Quoted source text, attributed separately from HOL analysis.