CVE-2026-48959: IO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop in
Source GCVE Database
Not known to be exploited · CVSS 7.5 High : upgrade to 2.220 soon.
Data as of 10 Nov 2026, 16:36 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 7.5 |
|---|
- Patch
- Available – fixed in 2.220
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade IO::Uncompress::Unzip and IO-Compress to 2.220.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| IO::Uncompress::UnzipIO-Compress | Affected
| Fixed in
|
CPANIO-Compresspkg:cpan/IO-CompressOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- nvd.nist.gov/vuln/detail/CVE-2026-48959 (opens in a new tab)
- github.com/pmqs/IO-Compress/commit/68db44076f4c1a86a2ffe53a958eac6cabaf72e2.patch (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
- metacpan.org/release/PMQS/IO-Compress-2.220/changes (opens in a new tab)
- openwall.com/lists/oss-security/2026/05/27/2 (opens in a new tab)