CVE-2026-82327: Libsolv: libsolv: out-of-bounds write in repo_write() via unvalidated directory id from vertical/paged .solv filelist data

Vulnerability summary

CVE-2026-82327 is a medium (CVSS 5.5) Improper Validation of Array Index vulnerability in libsolv. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 5.4% of scored vulnerabilities.

Timeline

1. 28-08-2026
   PublishedVulnerability first disclosed.
2. 21-10-2026
   Last modifiedVulnerability information updated.

Description

A flaw was found in libsolv, a dependency-resolution library used by RPM-based package managers such as dnf and zypper to work with .solv repository cache files. When libsolv rewrites a .solv cache file, it reads directory-id values from the file's compressed filelist data without validating that they fall within the expected range. A corrupted or specially crafted .solv cache file (for example, one left in a torn state after an unclean system shutdown) can cause an out-of-bounds memory write when a tool such as dnf, yum, or zypper next processes it. Successful exploitation is expected to result in a crash of the affected tool (denial of service); it is not expected to allow arbitrary code execution because the out-of-bounds write always stores a fixed, non-attacker-controlled value.

• CWE-129Improper Validation of Array IndexThe product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.