CVE-2026-64053: Linux kernel · block: don't overwrite bip_vcnt in bio_integrity_copy_user()
Affects Linux kernelSource CVE Database V5
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 2026
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
Upgrade Linux kernel to d18160c9525c63c203656fefd847e94b538cd4a4, 637ad3a56a3b889527d1dacea6fea2a8bd648140, 066be1439593a381b1a29663becfcfe0c92363e7 or 0d48654af4d1390c888389206cc13b51b82c30e6.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| 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
- git.kernel.org/stable/c/d18160c9525c63c203656fefd847e94b538cd4a4 (opens in a new tab)
- git.kernel.org/stable/c/0d48654af4d1390c888389206cc13b51b82c30e6 (opens in a new tab)
- git.kernel.org/stable/c/066be1439593a381b1a29663becfcfe0c92363e7 (opens in a new tab)
- git.kernel.org/stable/c/637ad3a56a3b889527d1dacea6fea2a8bd648140 (opens in a new tab)