CPANSA-IO-Compress-2026-48959: IO-Compress vulnerability
| Publisher | giterlizzi | Document category | csaf_security_advisory |
|---|---|---|---|
| Initial release date | 2026-05-27T00:00:00 | Engine | CSAF Perl Toolkit 0.26 |
| Current release date | 2026-05-27T00:00:00 | Build Date | |
| Current version | 1 | Status | final |
| CVSS v3.1 Base Score | 7.5 | Severity | |
| Original language | Language | en | |
| Also referred to | |||
Vulnerability Description
IO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop in fastForward. fastForward() compares length $offset (the digit count of the offset, 1 to 19) against the chunk size $c instead of $offset itself, so $c shrinks from 16 KiB to 1-19 bytes per iteration. Extracting a named entry from an attacker supplied zip via IO::Uncompress::Unzip->new($zip, Name => $target) drives a per-byte read loop scaling with the entry's compressed size, up to the non-Zip64 4 GiB cap.
Vulnerabilities
CVE-2026-48959
Vulnerability DescriptionIO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop in fastForward.
fastForward() compares length $offset (the digit count of the offset, 1 to 19) against the chunk size $c instead of $offset itself, so $c shrinks from 16 KiB to 1-19 bytes per iteration.
Extracting a named entry from an attacker supplied zip via IO::Uncompress::Unzip->new($zip, Name => $target) drives a per-byte read loop scaling with the entry's compressed size, up to the non-Zip64 4 GiB cap.
| Weakness | CWE-407 : Inefficient Algorithmic Complexity |
|---|
Product status
Known affected
| Product | Score | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| IO-Compress less than 2.220 |
|
Fixed
- IO-Compress greater than or equal 2.220
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
- CPANSA-IO-Compress-2026-48959 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-io-compress-2026-48959.json - https://github.com/pmqs/IO-Compress/commit/68db44076f4c1a86a2ffe53a958eac6cabaf72e2.patch external
https://github.com/pmqs/IO-Compress/commit/68db44076f4c1a86a2ffe53a958eac6cabaf72e2.patch - https://metacpan.org/release/PMQS/IO-Compress-2.220/changes external
https://metacpan.org/release/PMQS/IO-Compress-2.220/changes - http://www.openwall.com/lists/oss-security/2026/05/27/2 external
http://www.openwall.com/lists/oss-security/2026/05/27/2 - CVE-2026-48959 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2026-48959
Revision history
| Version | Date of the revision | Summary of the revision |
|---|---|---|
| 1 | Wed May 27 00:00:00 2026 | First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/