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.

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Fixes

Solution

Upgrade to version 1.36 or later.


Workaround

For deployments that cannot upgrade, enforce a maximum length on strings before passing them to the trim and rtrim functions. Note that the HTML form field maxlength attribute is only enforced client-side.

History

Tue, 07 Jul 2026 22:45:00 +0000

Type Values Removed Values Added
Description 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.
Title String::Util versions before 1.36 for Perl are susceptible to a regular expression denial of service
Weaknesses CWE-1333
References

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cve-icon MITRE

Status: PUBLISHED

Assigner: CPANSec

Published:

Updated: 2026-07-08T00:28:33.750Z

Reserved: 2026-07-06T18:31:10.251Z

Link: CVE-2026-14895

cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses