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Vulnerability record · CVE-2026-81721 · published 27 August 2026

CVE-2026-81721: Jahlives openssl encrypt uncontrolled resource consumption vulnerability

JJahlives · Openssl Encrypt

openssl_encrypt before 1.4.9 fails to validate KDF cost parameters in encrypted file metadata and keystore headers, allowing attackers to trigger unbounded memory allocation. Attackers can craft malicious encrypted files declaring arbitrarily large Argon2, scrypt, or balloon KDF parameters to exhaust system memory and crash the process without authentication.

8.7 CVSS 4.0 High EPSS 0.58% · top 54.5% CWE-400 · Uncontrolled resource consumption
8.7CVSS 4.0 base score
0.58%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
2 Sep 2026Last modified by NVD

Description

openssl_encrypt before 1.4.9 fails to validate KDF cost parameters in encrypted file metadata and keystore headers, allowing attackers to trigger unbounded memory allocation. Attackers can craft malicious encrypted files declaring arbitrarily large Argon2, scrypt, or balloon KDF parameters to exhaust system memory and crash the process without authentication.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-7894-5gw8-69hr Vendor Advisory
https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-kdf-2 Third Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-81721), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.