CVE-2026-80961

HIGHCVSS 7.8/10EPSS 0.20%

Last modified

CVE-2026-80961 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: dm-pcache: validate kset key_num and intra-segment bounds Two more fields decoded from the cache device go unbounded. The kset key_num drives cache_kset_crc() and the replay loop in cache_replay(), the writeback worker and the GC worker, but only the magic and a fixed-seed CRC are checked first, so a non-last kset whose key_num exceeds the PCACHE_KSET_KEYS_MAX buffer reads past its end before the CRC compare. A key's intra-segment offset and length in cache_key_decode() are taken verbatim, so a key running past its segment is replayed into the cache tree and the data CRC check and every later read hit then copy adjacent persistent memory into the caller's bio -- an out-of-bounds read that leaks to user space. EPSS estimates a 0.20% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: dm-pcache: validate kset key_num and intra-segment bounds Two more fields decoded from the cache device go unbounded. The kset key_num drives cache_kset_crc() and the replay loop in cache_replay(), the writeback worker and the GC worker, but only the magic and a fixed-seed CRC are checked first, so a non-last kset whose key_num exceeds the PCACHE_KSET_KEYS_MAX buffer reads past its end before the CRC compare. A key's intra-segment offset and length in cache_key_decode() are taken verbatim, so a key running past its segment is replayed into the cache tree and the data CRC check and every later read hit then copy adjacent persistent memory into the caller's bio -- an out-of-bounds read that leaks to user space. Both fields are controlled by whoever supplies the cache device (CAP_SYS_ADMIN); the CRC seed is public. Add kset_onmedia_valid() to bound key_num before any kset read, and reject a key whose offset plus length, computed in 64 bits, exceeds the segment data_size. Valid metadata is unaffected.

Metrics

EPSS Probability
0.20%

9.7th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0, < d8caf96040a06096276ab72f5e1e8547c014c564; >= 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0, < 5ac38f4b4862fad6e7270fde5c3356a822ce74ca; >= 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0, < f11deb032fd84081e7831cffcba895d893054a22
LinuxLinux6.18

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-80961?
In the Linux kernel, the following vulnerability has been resolved: dm-pcache: validate kset key_num and intra-segment bounds Two more fields decoded from the cache device go unbounded. The kset key_num drives cache_kset_crc() and the replay loop in cache_replay(), the writeback worker and the GC worker, but only the magic and a fixed-seed CRC are checked first, so a non-last kset whose key_num exceeds the PCACHE_KSET_KEYS_MAX buffer reads past its end before the CRC compare. A key's intra-segment offset and length in cache_key_decode() are taken verbatim, so a key running past its segment is replayed into the cache tree and the data CRC check and every later read hit then copy adjacent persistent memory into the caller's bio -- an out-of-bounds read that leaks to user space. Both fields are controlled by whoever supplies the cache device (CAP_SYS_ADMIN); the CRC seed is public. Add kset_onmedia_valid() to bound key_num before any kset read, and reject a key whose offset plus length, computed in 64 bits, exceeds the segment data_size. Valid metadata is unaffected.
How severe is CVE-2026-80961?
CVE-2026-80961 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.20% probability of exploitation in the next 30 days.
How do I fix CVE-2026-80961?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST