CVE-2026-48961: IO::Compress versions from 2.207 before 2.220 for Perl ship a zipdetails CLI tool that crashes with undefined subroutine on Info-ZIP Unix Extra Field with 8-byte UID or GID

Severity: high (CVSS 7.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-27 · updated 2026-07-24
Weakness: CWE-755

Description

IO::Compress versions from 2.207 before 2.220 for Perl ship a zipdetails CLI tool that crashes with undefined subroutine on Info-ZIP Unix Extra Field with 8-byte UID or GID. When decode_ux() in bin/zipdetails handles an Info-ZIP Unix Extra Field (tag 0x7875) with UID Size or GID Size set to 8, causing zipdetails to decode an 8-byte UID or GID value, it dispatches through decodeLitteEndian(), which calls a misnamed helper unpackValueQ. The actual function defined in the same file is unpackValue_Q (with underscore); the call raises 'Undefined subroutine &main::unpackValueQ' and the script exits with status 255. Library callers of IO::Compress and IO::Uncompress are not affected; the defect is in the bundled CLI tool.

Affected products

PMQS IO::Compress: from 2.207 before 2.220 — fixed in 2.220

How to fix

Upgrade to a fixed version: PMQS IO::Compress 2.220. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-48961 or the next vulnerability affects your stack