String::Util versions before 1.36 for Perl are susceptible to a regular expression denial of service

published 2026-07-07 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-42127

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits: 0; none known

String::Util versions before 1.36 for Perl are susceptible to a regular expression denial of service.

The trim and rtrim functions stripped trailing whitespace with s/\s*$//u. Because \s* matches greedily and the $ anchor fails whenever a non-whitespace character follows the whitespace, the regex engine retries the match at each offset of a long whitespace run, producing quadratic backtracking. The fix replaces \s*$ with \s+$.

Any caller that passes untrusted input to trim or rtrim can trigger CPU exhaustion with a string containing a long run of whitespace.

Patch / fix

fixed in 1 distros 1 links 1

BAKERSCOT String::Util 1.36

libstring-util-perl Debian 14 1.36-1

debian advisories DEBIAN-CVE-2026-14895

github.com/scottchiefbaker/String-Util@f815086 commit

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 4 mo ago (2026-07-08)

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

BAKERSCOT String::Util

Classification

Weakness

CWE-1333 Inefficient Regular Expression Complexity

References

Sources

CVE List CVE-2026-14895
NVD CVE-2026-14895

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary