CVE-2026-48959
CVE-2026-48959 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-407.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 0% (29th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-32043
- Weakness: CWE-407
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-48959?
- 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.
- How severe is CVE-2026-48959?
- CVE-2026-48959 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2026-48959 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-48959?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-48959 have an EU (EUVD) identifier?
- Yes. CVE-2026-48959 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32043.
- When was CVE-2026-48959 published?
- CVE-2026-48959 was published on 2026-05-27 and last updated on 2026-06-17.
References
- https://github.com/pmqs/IO-Compress/commit/68db44076f4c1a86a2ffe53a958eac6cabaf72e2.patch
- https://metacpan.org/release/PMQS/IO-Compress-2.220/changes
- http://www.openwall.com/lists/oss-security/2026/05/27/2
Other CWE-407 vulnerabilities
- CVE-2026-58226 — High (CVSS 8.7): Inefficient Algorithmic Complexity vulnerability in elixir-mint hpax allows unauthenticated denial-of-service via…
- CVE-2026-54892 — High (CVSS 8.7): Inefficient algorithmic complexity in Plug's nested-parameter decoder allows an unauthenticated remote attacker to…
- CVE-2026-59094 — High (CVSS 7.5): Pathway through 0.31.1, fixed in commit d09722e, document store applies a caller-supplied glob pattern to indexed…
- CVE-2026-53433 — High (CVSS 7.5): fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to…
- CVE-2026-13311 — High (CVSS 7.5): shell-quote prior to 1.8.5 finalizes parsed tokens in parse() using Array.prototype.concat as a reduce accumulator,…
- CVE-2026-48516 — High (CVSS 7.5): MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7,…