CVE-2026-11793: Stack-based Buffer Overflow in Red Hat Red Hat Directory Server 11
CVE-2026-11793 is a stack-based buffer overflow vulnerability in Red Hat Directory Server 11's 389 Directory Server. The flaw exists in the checkPrefix() function in pw. c, which copies an attacker-controlled algorithm ID into a fixed 256-byte stack buffer without bounds checking when parsing reversible-encrypted attribute values. An attacker with Directory Manager privileges can exploit this by storing a crafted credential with an oversized algorithm ID, causing the LDAP server to crash. The FORTIFY_SOURCE feature mitigates this vulnerability to denial of service only.
AI Analysis
Technical Summary
This vulnerability involves a stack buffer overflow in the checkPrefix() function of the 389 Directory Server component of Red Hat Directory Server 11. The function copies an algorithm ID from reversible-encrypted attribute values into a 256-byte stack buffer without validating its length, allowing an attacker with Directory Manager privileges to trigger a buffer overflow by providing an oversized algorithm ID. Exploitation results in a denial of service via server crash. The FORTIFY_SOURCE compiler feature reduces the impact to denial of service rather than arbitrary code execution. No patch or official remediation level has been confirmed in the vendor advisory as of the publication date.
Potential Impact
The vulnerability allows an attacker with Directory Manager privileges to cause a denial of service by crashing the LDAP server through a crafted credential containing an oversized algorithm ID. There is no impact on confidentiality or integrity reported. The vulnerability does not appear to allow code execution due to FORTIFY_SOURCE mitigation.
Mitigation Recommendations
Patch status is not yet confirmed — check the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-11793 for current remediation guidance. Until a patch is available, limit Directory Manager privileges to trusted users only to reduce risk. The FORTIFY_SOURCE mitigation reduces the impact to denial of service only.
CVE-2026-11793: Stack-based Buffer Overflow in Red Hat Red Hat Directory Server 11
Description
CVE-2026-11793 is a stack-based buffer overflow vulnerability in Red Hat Directory Server 11's 389 Directory Server. The flaw exists in the checkPrefix() function in pw. c, which copies an attacker-controlled algorithm ID into a fixed 256-byte stack buffer without bounds checking when parsing reversible-encrypted attribute values. An attacker with Directory Manager privileges can exploit this by storing a crafted credential with an oversized algorithm ID, causing the LDAP server to crash. The FORTIFY_SOURCE feature mitigates this vulnerability to denial of service only.
CVSS v3.1
Score 4.9medium
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a stack buffer overflow in the checkPrefix() function of the 389 Directory Server component of Red Hat Directory Server 11. The function copies an algorithm ID from reversible-encrypted attribute values into a 256-byte stack buffer without validating its length, allowing an attacker with Directory Manager privileges to trigger a buffer overflow by providing an oversized algorithm ID. Exploitation results in a denial of service via server crash. The FORTIFY_SOURCE compiler feature reduces the impact to denial of service rather than arbitrary code execution. No patch or official remediation level has been confirmed in the vendor advisory as of the publication date.
Potential Impact
The vulnerability allows an attacker with Directory Manager privileges to cause a denial of service by crashing the LDAP server through a crafted credential containing an oversized algorithm ID. There is no impact on confidentiality or integrity reported. The vulnerability does not appear to allow code execution due to FORTIFY_SOURCE mitigation.
Mitigation Recommendations
Patch status is not yet confirmed — check the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-11793 for current remediation guidance. Until a patch is available, limit Directory Manager privileges to trusted users only to reduce risk. The FORTIFY_SOURCE mitigation reduces the impact to denial of service only.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- redhat
- Date Reserved
- 2026-06-09T13:04:58.380Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-11793","vendor":"Red Hat"}]
Threat ID: 6a28145b8dd33fbd85364a3a
Added to database: 6/9/2026, 1:25:47 PM
Last enriched: 6/9/2026, 1:40:48 PM
Last updated: 6/9/2026, 2:56:54 PM
Views: 6
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