CVE-2026-11774 389-ds-base: 389-ds-base: integer overflow in sasl packet length bypasses size limit leading to heap buffer overflow
Remote attackers with valid SASL credentials can trigger an integer overflow to bypass size limits, causing heap buffer overflow and potential remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-11774?
CVE-2026-11774 is a high-severity vulnerability in Red Hat Directory Server 11.5 E4S for RHEL 8, published on 11 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
An integer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), adding sizeof(uint32_t) to a crafted SASL packet length prefix of 0xFFFFFFFC causes unsigned wraparound to zero, bypassing the nsslapd-maxsasliosize limit and leading to a heap buffer overflow of up to approximately 2 megabytes of attacker-controlled data. After a successful SASL bind with integrity protection (SSF > 0), a remote attacker can cause a Denial of Service (DoS) or achieve Remote Code Execution (RCE). In FreeIPA and Red Hat Identity Management deployments, any domain user with a valid Kerberos ticket, enrolled host, or service account can trigger this vulnerability over the network. This flaw is independent of CVE-2025-14905, which patched schema.c only and did not modify sasl_io.c.
Weakness: CWE-190
Which versions are affected by CVE-2026-11774?
How do I fix CVE-2026-11774?
Apply the vendor's patch.
Is CVE-2026-11774 being exploited?
There is no known exploitation of CVE-2026-11774 in the wild and no public exploit code.
Sources
Also known as CLSA-2026-1784639752, DEBIAN-CVE-2026-11774, GHSA-6mrg-rm5v-2c3q, UBUNTU-CVE-2026-11774.