CVE-2026-11793

Description

A stack buffer overflow flaw was found in 389 Directory Server. The checkPrefix() function in pw.c copies an attacker-controlled algorithm ID into a 256-byte stack buffer without bounds checking when parsing reversible-encrypted attribute values. An attacker with Directory Manager privileges can crash the LDAP server by storing a crafted credential with an oversized algorithm ID. FORTIFY_SOURCE mitigates this to denial of service only.

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CVSS v3.1 Score

4.9

MEDIUM

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

EPSS — Exploit Prediction

0.0028

Probability of exploitation

0.20%

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-121 CWE-121

Affected Products

Vendor	Product	Versions
redhat	389_directory_server	All

References

Advisories & Patches

https://access.redhat.com/security/cve/CVE-2026-11793 https://bugzilla.redhat.com/show_bug.cgi?id=2484914

Other References

https://redhat.atlassian.net/browse/PSIRTSUPT-7600

Frequently Asked Questions

What is CVE-2026-11793? +

A stack buffer overflow flaw was found in 389 Directory Server. The checkPrefix() function in pw.c copies an attacker-controlled algorithm ID into a 256-byte stack buffer without bounds checking when parsing reversible-encrypted attribute values. An attacker with Directory Manager privileges can crash the LDAP server by storing a crafted credential with an oversized algorithm ID. FORTIFY_SOURCE mitigates this to denial of service only. It has a CVSS v3.1 base score of 4.9 (MEDIUM).

How severe is CVE-2026-11793? +

CVE-2026-11793 has a CVSS v3.1 score of 4.9 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0028, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-11793? +

CVE-2026-11793 affects products from redhat, specifically: 389_directory_server. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-11793? +

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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