CVE-2026-31786

Advisory lineage Upstream: 0 Downstream: 7
Analyzed
Published: 30 Apr 2026, 10:31
Last modified:14 Jun 2026, 17:44

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.2% LOW
0% probability +0.19%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

30 Apr 2026, 10:31
Published
Vulnerability first disclosed
14 Jun 2026, 17:44
Last Modified
Vulnerability information updated

Description

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

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.20%• Percentile: 10%

Techniques & Countermeasures

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • linux•linux

    ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < e3af585e1728c917682b6a3de9a69b41fb9194d4 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 8288d031a01dbacfde3fc643f7be3d23504de64d | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < f458ba102da97fafca106327086fc95f3fc764cb | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 4b4defd2fce3f966c25adabf46644a85558f1169 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0a | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < d5f59216650c51e5e3fcb7517c825bc8047f60ef | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 52cecff98bda2c51eed1c6ce9d21c5d6268fb19d | ≥ 84b7625728ea311ea35bdaa0eded53c1c56baeaa, < e3af585e1728c917682b6a3de9a69b41fb9194d4 | ≥ 84b7625728ea311ea35bdaa0eded53c1c56baeaa, < 8288d031a01dbacfde3fc643f7be3d23504de64d | ≥ 84b7625728ea311ea35bdaa0eded53c1c56baeaa, < f458ba102da97fafca106327086fc95f3fc764cb | ≥ 84b7625728ea311ea35bdaa0eded53c1c56baeaa, < 4b4defd2fce3f966c25adabf46644a85558f1169 | ≥ 84b7625728ea311ea35bdaa0eded53c1c56baeaa, < 5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0a | ≥ 84b7625728ea311ea35bdaa0eded53c1c56baeaa, < d5f59216650c51e5e3fcb7517c825bc8047f60ef | ≥ 84b7625728ea311ea35bdaa0eded53c1c56baeaa, < 52cecff98bda2c51eed1c6ce9d21c5d6268fb19d | ≥ 84b7625728ea311ea35bdaa0eded53c1c56baeaa, < 27fdbab4221b375de54bf91919798d88520c6e28 | 4.13

  • linux•linux_kernel

    ≥ 4.13, < 5.10.254 | ≥ 5.11, < 5.15.204 | ≥ 5.16, < 6.1.170 | ≥ 6.2, < 6.6.137 | ≥ 6.7, < 6.12.85 | ≥ 6.13, < 6.18.26 | ≥ 6.19, < 7.0.3 | 7.1:rc1 | 7.1:rc2

References (10)