CVE-2026-31786 (GCVE-0-2026-31786)

Vulnerability from cvelistv5 – Published: 2026-04-30 10:31 – Updated: 2026-06-14 17:44
VLAI
Title
Buffer overflow in drivers/xen/sys-hypervisor.c
Summary
In the Linux kernel, the following vulnerability has been resolved: Buffer overflow in drivers/xen/sys-hypervisor.c The build id returned by HYPERVISOR_xen_version(XENVER_build_id) is neither NUL terminated nor a string. The first causes a buffer overflow as sprintf in buildid_show will read and copy till it finds a NUL. 00000000 f4 91 51 f4 dd 38 9e 9d 65 47 52 eb 10 71 db 50 |..Q..8..eGR..q.P| 00000010 b9 a8 01 42 6f 2e 32 |...Bo.2| 00000017 So use a memcpy instead of sprintf to have the correct value: 00000000 f4 91 51 f4 dd 00 9e 9d 65 47 52 eb 10 71 db 50 |..Q.....eGR..q.P| 00000010 b9 a8 01 42 |...B| 00000014 (the above have a hack to embed a zero inside and check it's returned correctly). This is XSA-485 / CVE-2026-31786
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 84b7625728ea311ea35bdaa0eded53c1c56baeaa , < e3af585e1728c917682b6a3de9a69b41fb9194d4 (git)
Affected: 84b7625728ea311ea35bdaa0eded53c1c56baeaa , < 8288d031a01dbacfde3fc643f7be3d23504de64d (git)
Affected: 84b7625728ea311ea35bdaa0eded53c1c56baeaa , < f458ba102da97fafca106327086fc95f3fc764cb (git)
Affected: 84b7625728ea311ea35bdaa0eded53c1c56baeaa , < 4b4defd2fce3f966c25adabf46644a85558f1169 (git)
Affected: 84b7625728ea311ea35bdaa0eded53c1c56baeaa , < 5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0a (git)
Affected: 84b7625728ea311ea35bdaa0eded53c1c56baeaa , < d5f59216650c51e5e3fcb7517c825bc8047f60ef (git)
Affected: 84b7625728ea311ea35bdaa0eded53c1c56baeaa , < 52cecff98bda2c51eed1c6ce9d21c5d6268fb19d (git)
Affected: 84b7625728ea311ea35bdaa0eded53c1c56baeaa , < 27fdbab4221b375de54bf91919798d88520c6e28 (git)
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Linux Linux Affected: 4.13
Unaffected: 0 , < 4.13 (semver)
Unaffected: 5.10.254 , ≤ 5.10.* (semver)
Unaffected: 5.15.204 , ≤ 5.15.* (semver)
Unaffected: 6.1.170 , ≤ 6.1.* (semver)
Unaffected: 6.6.137 , ≤ 6.6.* (semver)
Unaffected: 6.12.85 , ≤ 6.12.* (semver)
Unaffected: 6.18.26 , ≤ 6.18.* (semver)
Unaffected: 7.0.3 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.