Vulnerability in Fractal String\

CVE-2024-13939

String::Compare::ConstantTime for Perl through 0.321 is vulnerable to timing attacks that allow an attacker to guess the length of a secret string. As stated in the documentation: "If the lengths of the strings are different, because equals returns false right away the size of the secret string may be leaked (but not its contents)." This is similar to CVE-2020-36829

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2024-13939: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2024-13939?
CVE-2024-13939 is a high-severity vulnerability in Fractal String\, classified under CWE-208. CVSS score: 7.5/10. Published 2025-03-28.
How severe is CVE-2024-13939?
High severity. CVSS v3 base score is 7.5 out of 10.