KDC memory disclosure and crash via LDAP underflow
Published Jun 11, 2026 · Updated Jun 11, 2026
Integer underflow in Red Hat krb5's LDAP KDB plugin allows attackers controlling the LDAP backend to crash the KDC or kadmind. The berval2tl_data() function subtracts two from a zero- or one-byte krbExtraData length, wraps the unsigned result, allocates the truncated size, and copies up to 65,534 bytes from the short buffer. Exploitation requires control of a configured LDAP KDB backend and causes a heap out-of-bounds read, exposing adjacent process memory or interrupting service.
Summary
What happened
Integer underflow in Red Hat krb5's LDAP KDB plugin allows attackers controlling the LDAP backend to crash the KDC or kadmind. The berval2tl_data() function subtracts two from a zero- or one-byte krbExtraData length, wraps the unsigned result, allocates the truncated size, and copies up to 65,534 bytes from the short buffer. Exploitation requires control of a configured LDAP KDB backend and causes a heap out-of-bounds read, exposing adjacent process memory or interrupting service.
The record
- CVE
- CVE-2026-11850
- Published
- Jun 11, 2026
- Updated
- Jun 11, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 6
- Classifications
- CWE-191, T1499.004
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Jun 11, 2026CVE publishedPublication date reported by the CVE source.
- Jun 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo