CVE-2026-81687: DoS (CVSS 5.5)

Description

openssl_encrypt versions before 1.4.9 fail to enforce a time ceiling on key derivation function iteration counts specified in file metadata. Attackers can craft files with extremely high KDF iteration counts to consume CPU resources for unbounded periods before password verification occurs.

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0021

Probability of exploitation

0.11%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-400 Uncontrolled Resource Consumption

References

Other References

https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-rv6w-7hq9-pr74 https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-kdf

Frequently Asked Questions

What is CVE-2026-81687? +

openssl_encrypt versions before 1.4.9 fail to enforce a time ceiling on key derivation function iteration counts specified in file metadata. Attackers can craft files with extremely high KDF iteration counts to consume CPU resources for unbounded periods before password verification occurs. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2026-81687? +

CVE-2026-81687 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0021, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-81687? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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