CVE-2026-42495 | BDVDB-2026-353236 Detail
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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.
Impact#
A guest using pygrub can escalate its privilege to that of the domain construction tools (i.e., normally, to control of the host). If the mechanism introduced by XSA-443 (see the mitigation section below) is in use, then the guest can only escalate to this limited context.
Weaknesses#
- CWE-191 Integer Underflow (Wrap or Wraparound)
References#
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.