CVE-2026-48959 | IO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop in fastForward

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.

Published: 2026-05-27 Last update: 2026-05-29 Assigner: 9b29abf9-4ab0-4765-b253-1875cd9b441e Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-48959 is rated Low Risk (35.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-48959

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-02 0.02% 0.05% +0.03%
2 2026-05-27 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-48959

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-48959

GitHub Security Advisory for CVE-2026-48959

GHSA-7vxx-5gqr-7r44 · Severity: high — IO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop...

OS Trackers for CVE-2026-48959

vendor priority summary link
debian not yet assigned CVE-2026-48959 not yet assigned priority: Debian including 2 source packages (libio-compress-perl, perl), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 6, resolved 4. https://security-tracker.debian.org/tracker/CVE-2026-48959
ubuntu medium CVE-2026-48959 medium priority: Ubuntu including 2 source packages (libio-compress-perl, perl), 16 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): needs-triage 16. https://ubuntu.com/security/CVE-2026-48959

Affected software / configurations for CVE-2026-48959

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-48959

cvelogic Threat Intelligence