CVE-2026-11793: Stack-based Buffer Overflow in Red Hat Red Hat Directory Server 11
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.
AI Analysis
Technical Summary
This vulnerability involves a stack buffer overflow in the checkPrefix() function of pw.c in Red Hat Directory Server 11 (389 Directory Server). The function copies an attacker-controlled algorithm ID into a 256-byte stack buffer without proper 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 presence of FORTIFY_SOURCE reduces the impact to denial of service rather than arbitrary code execution.
Potential Impact
The vulnerability allows an attacker with Directory Manager privileges to cause a denial of service by crashing the LDAP server. There is no impact on confidentiality or integrity, only availability is affected. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory at https://access.redhat.com/security/cve/CVE-2026-11793 for current remediation guidance. Until a patch is available, restrict Directory Manager privileges to trusted users only to reduce risk. The FORTIFY_SOURCE mitigation limits the impact to denial of service.
CVE-2026-11793: Stack-based Buffer Overflow in Red Hat Red Hat Directory Server 11
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.
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 pw.c in Red Hat Directory Server 11 (389 Directory Server). The function copies an attacker-controlled algorithm ID into a 256-byte stack buffer without proper 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 presence of FORTIFY_SOURCE reduces the impact to denial of service rather than arbitrary code execution.
Potential Impact
The vulnerability allows an attacker with Directory Manager privileges to cause a denial of service by crashing the LDAP server. There is no impact on confidentiality or integrity, only availability is affected. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory at https://access.redhat.com/security/cve/CVE-2026-11793 for current remediation guidance. Until a patch is available, restrict Directory Manager privileges to trusted users only to reduce risk. The FORTIFY_SOURCE mitigation limits the impact to denial of service.
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: 06/09/2026, 13:25:47 UTC
Last enriched: 06/30/2026, 22:19:58 UTC
Last updated: 07/31/2026, 19:22:57 UTC
Views: 112
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