CVE-2026-81686: Input Validation Flaw (CVSS 6.2)

Description

openssl_encrypt 1.4.x before 1.4.9 contains an optional D-Bus crypto service whose org.freedesktop.DBus.Properties.Set method performs neither a polkit authorization check nor value validation. Any local user on the system bus can call Set without authorization and set MaxConcurrentOperations (to 0/negative, causing the concurrency gate to refuse all subsequent operations, or to a huge value removing the limit) or the unbounded DefaultTimeout, resulting in a persistent denial of service of the root daemon. The D-Bus service exists only on the 1.4.x line and was removed in 1.5.x.

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CVSS v3.1 Score

6.2

MEDIUM

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

EPSS — Exploit Prediction

0.0010

Probability of exploitation

0.01%

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-20 Improper Input Validation

References

Other References

https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-7fhx-8rmv-qjj3 https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-d-bus-properties-authorization-bypass

Frequently Asked Questions

What is CVE-2026-81686? +

openssl_encrypt 1.4.x before 1.4.9 contains an optional D-Bus crypto service whose org.freedesktop.DBus.Properties.Set method performs neither a polkit authorization check nor value validation. Any local user on the system bus can call Set without authorization and set MaxConcurrentOperations (to 0/negative, causing the concurrency gate to refuse all subsequent operations, or to a huge value removing the limit) or the unbounded DefaultTimeout, resulting in a persistent denial of service of the root daemon. The D-Bus service exists only on the 1.4.x line and was removed in 1.5.x. It has a CVSS v3.1 base score of 6.2 (MEDIUM).

How severe is CVE-2026-81686? +

CVE-2026-81686 has a CVSS v3.1 score of 6.2 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0010, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-81686? +

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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