Vulnerability · Published Jul 28, 2026 · Assigned by XEN
CVE-2026-42494buffer overruns in libfsimage iso9660 handling
Medium 6.1
In plain English
A medium-severity out-of-bounds read in Xen from Xen. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] The directory and Rock Ridge / SUSP walk in libfsimage's iso9660 driver derives several lengths directly from attacker-controlled on-disk fields without validating them: * The directory loop itself assumes a good record length. This is CVE-2026-42494. * The calculation of the System Use area may underflow. This is CVE-2026-42495. * The Rock Ridge extension loop assumes a good (inner) record length. This is CVE-2026-62423. * The Rock Ridge NM record processing assumes a good entry length. This is CVE-2026-62424. * The Rock Ridge CE record processing assumes a good size and offset. This is CVE-2026-62425.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.21 | xen | 4.19.6-r0 | ALPINE-CVE-2026-42494 |
| Alpine:v3.22 | xen | 4.20.4-r0 | ALPINE-CVE-2026-42494 |
| Alpine:v3.23 | xen | 4.20.4-r0 | ALPINE-CVE-2026-42494 |
| Alpine:v3.24 | xen | 4.21.2-r0 | ALPINE-CVE-2026-42494 |
| Debian:12 | xen | 4.17.7-0+deb12u1 | DEBIAN-CVE-2026-42494 |
| Debian:13 | xen | 4.20.3+127-gc42374a105-0+deb13u1 | DEBIAN-CVE-2026-42494 |
| Debian:14 | xen | 4.20.3+127-gc42374a105-1 | DEBIAN-CVE-2026-42494 |
| Ubuntu:22.04:LTS | xen | no fix listed | UBUNTU-CVE-2026-42494 |
| Ubuntu:24.04:LTS | xen | no fix listed | UBUNTU-CVE-2026-42494 |
| Ubuntu:26.04:LTS | xen | no fix listed | UBUNTU-CVE-2026-42494 |
| Ubuntu:26.10 | xen | no fix listed | UBUNTU-CVE-2026-42494 |
Affected products (as reported)
Weakness: CWE-125 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H