CyberSecBulletin
CVE-2026-48961NVD status: Deferred

IO::Compress: Improper Handling of Exceptional Conditions

Published Updated By the CyberSecBulletin desk

CVE-2026-48961 is a high-severity improper handling of exceptional conditions vulnerability in IO::Compress from PMQS, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2.220 as the first without the flaw, so updating IO::Compress to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.26% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update IO::Compress to 2.220 or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
PMQSIO::Compress2.207 up to, but not including, 2.2202.220

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
LowSome restricted data can be read.
Integrity
LowLimited modification of data is possible.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. Scored by CISA (ADP).

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Handling of Exceptional Conditions

The product does not handle or incorrectly handles an exceptional condition.

More Improper Handling of Exceptional Conditions vulnerabilities (CWE-755)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in IO::Compress

All IO::Compress vulnerabilities

Recent Improper Handling of Exceptional Conditions vulnerabilities

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