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VulnerabilityPublished Updated

CVE-2026-64053: Linux kernel · block: don't overwrite bip_vcnt in bio_integrity_copy_user()

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in d18160c9525c63c203656fefd847e94b538cd4a4 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in d18160c9525c63c203656fefd847e94b538cd4a4, 637ad3a56a3b889527d1dacea6fea2a8bd648140, 066be1439593a381b1a29663becfcfe0c92363e7 +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 19 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 Linux kernel to d18160c9525c63c203656fefd847e94b538cd4a4, 637ad3a56a3b889527d1dacea6fea2a8bd648140, 066be1439593a381b1a29663becfcfe0c92363e7 or 0d48654af4d1390c888389206cc13b51b82c30e6.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 3991657ae7074c3c497bf095093178bed37ea1b4, < d18160c9525c63c203656fefd847e94b538cd4a4
Fixed in
  • d18160c9525c63c203656fefd847e94b538cd4a4
LinuxLinuxAffected
  • ≥ 3991657ae7074c3c497bf095093178bed37ea1b4, < 637ad3a56a3b889527d1dacea6fea2a8bd648140
Fixed in
  • 637ad3a56a3b889527d1dacea6fea2a8bd648140
LinuxLinuxAffected
  • ≥ 3991657ae7074c3c497bf095093178bed37ea1b4, < 066be1439593a381b1a29663becfcfe0c92363e7
Fixed in
  • 066be1439593a381b1a29663becfcfe0c92363e7
LinuxLinuxAffected
  • ≥ 3991657ae7074c3c497bf095093178bed37ea1b4, < 0d48654af4d1390c888389206cc13b51b82c30e6
Fixed in
  • 0d48654af4d1390c888389206cc13b51b82c30e6
LinuxLinuxAffected
  • =6.11
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: block: don't overwrite bip_vcnt in bio_integrity_copy_user() bio_integrity_add_page() already sets bip_vcnt to 1 for the bounce segment. Overwriting it with nr_vecs breaks bip_vcnt <= bip_max_vcnt on WRITE (bip_max_vcnt is 1), so the gap-merge checks in block/blk.h read past the bip_vec[] flex array. On READ the read is in bounds but lands on a saved user bvec instead of the bounce. The line was added for split propagation, but bio_integrity_clone() doesn't copy bip_vcnt and BIP_CLONE_FLAGS excludes BIP_COPY_USER.

References

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