netfilter: handle unreadable frags

Answer in brief

CVE-2026-64414 records a High severity (CVSS 7.5) vulnerability in netfilter: handle unreadable frags. 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 Jul 25, 2026Updated Sep 4, 2026Source checked Sep 21, 2026First seen by HOL Aug 5, 2026Material review Sep 4, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 5 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.5. 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.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:o:linux:linux_kernel::::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.2:rc1::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.2:rc2::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=65249feb6b3df9e17bab5911ee56fa7b0971e231 <3b13e7635795394705920cca1e1db7e4ca2e334b \|\| >=65249feb6b3df9e17bab5911ee56fa7b0971e231 <fc5bfe63bacf8a3ae307b62b34206406ca733354 \|\| >=65249feb6b3df9e17bab5911ee56fa7b0971e231 <57056be3ec12e7d9ecd20a60d4060f510e4f284c \|\| >=65249feb6b3df9e17bab5911ee56fa7b0971e231 <da5b58478a9c1b85608c9e40a3b8432d071b409e	3b13e7635795394705920cca1e1db7e4ca2e334b, fc5bfe63bacf8a3ae307b62b34206406ca733354, 57056be3ec12e7d9ecd20a60d4060f510e4f284c, da5b58478a9c1b85608c9e40a3b8432d071b409e
Linux/Linuxgeneric	6.12	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 3b13e7635795394705920cca1e1db7e4ca2e334b if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 4, 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: netfilter: handle unreadable frags sashiko reports: When an skb with unreadable fragments (such as from devmem TCP, where skb_frags_readable(skb) returns false) is processed by the u32 module, skb_copy_bits() will safely return a negative error code [..] xt_u32: bail out with hotdrop in this case. gather_frags: return -1, just as if we had no fragment header. nfnetlink_queue: restrict to the linear part. nfnetlink_log: restrict to the linear part. v2: - skb_zerocopy helpers don't copy readable flag, i.e. nfnetlink_queue is broken too xt_u32 shouldn't return true if hotdrop was set.

Quoted source text, attributed separately from HOL analysis.