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VulnerabilityPublished Updated

CVE-2026-80546: Linux kernel · s390/zcrypt: Improve CCA CPRB length and overflow checks

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in 584400144020f40365de3972c4763da520e7280e : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 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 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 584400144020f40365de3972c4763da520e7280e, 50fe5133dcb46449daf2435fa705264364411129, 35ac6754ba6da45fd193f5ce3f665f7490b830d5 +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 26 Aug 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 584400144020f40365de3972c4763da520e7280e, 50fe5133dcb46449daf2435fa705264364411129, 35ac6754ba6da45fd193f5ce3f665f7490b830d5 or 6.13.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • >=6.12.114 <6.13
Fixed in
  • 584400144020f40365de3972c4763da520e7280e
  • 50fe5133dcb46449daf2435fa705264364411129
  • 35ac6754ba6da45fd193f5ce3f665f7490b830d5
  • 6.13
LinuxLinuxAffected
  • =7.1
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Improve CCA CPRB length and overflow checks The xcrb_msg_to_type6cprb_msgx() function lacks proper input validation, creating security vulnerabilities: 1. Integer overflow after CEIL4 alignment: Signed int variables could overflow during 4-byte boundary alignment, causing undersized buffer allocations or incorrect bounds checking. 2. Missing minimum size validation: The CPRBX structure is copied from userspace without verifying sufficient buffer length. Undersized buffers cause uninitialized memory access when reading structure fields like cprbx.cprb_len and cprbx.domain. 3. Arithmetic overflow in sum calculations: Adding control block and data block sizes could overflow, bypassing size checks and enabling buffer overflows. Fix by using size_t for length calculations, adding U32_MAX boundary checks after alignment, validating minimum control block size before copying from userspace, and detecting sum calculation overflows.

References

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