CVE-2026-74882: openssl_encrypt before 1.4.0 Insecure Default Configuration

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-17 · updated 2026-08-31
Weakness: CWE-345

Description

openssl_encrypt versions before 1.4.0 contain an insecure default configuration that trusts the entire RFC 1918 private address space in IntegrityProxyConfig trusted_proxies. Attackers on private networks can forge client certificate headers to bypass mTLS authentication when ProxyAuth validation is relaxed or modified.

Affected products

jahlives openssl_encrypt: before 1.4.0 — fixed in 1.4.0

How to fix

Upgrade to a fixed version: jahlives openssl_encrypt 1.4.0. Check the vendor advisory for mitigations.

References

https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-2592-7m3g-7fq6
https://www.vulncheck.com/advisories/openssl-encrypt-before-insecure-default-configuration

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