CVE-2026-103547 Auth bypass in OpenBSD
Remote attackers can impersonate users via ldapd authentication result reuse, requiring ldapd to be enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-103547?
CVE-2026-103547 is a critical authentication bypass vulnerability in OpenBSD, published on 30 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In ldapd in OpenBSD 7.8 before errata 057 and 7.9 before errata 021, delegated BSD authentication results are correlated only by the LDAP child process client file descriptor and LDAP message ID. After a connection closes, a later connection that reuses the same file descriptor and message ID can receive the earlier authentication result. A remote attacker who can reach ldapd can complete a Bind as another identity. A missing connection can also cause a NULL pointer dereference. (ldapd is not enabled by default.)
Weakness: CWE-863
Which versions are affected by CVE-2026-103547?
How do I fix CVE-2026-103547?
No fix has been published for CVE-2026-103547 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-103547 being exploited?
There is no known exploitation of CVE-2026-103547 in the wild and no public exploit code.
Sources
Also known as GHSA-f239-ggxr-g679.