CVE-2026-11610
HIGH 8.8A heap buffer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). After a successful SASL bind with integrity protection (SSF > 0), an authenticated attacker can send a specially crafted oversized LDAP UNBIND packet that is copied into a 512-byte heap receive buffer without a bounds check in sasl_io_recv() in sasl_io.c. This allows up to approximately 2 megabytes of attacker-controlled data to overflow the buffer, causing a denial of service (server crash). In FreeIPA and Red Hat Identity Management deployments, any domain user with a valid Kerberos ticket, any enrolled host, or any service account can trigger this vulnerability over the network after authenticating via GSSAPI. The vulnerable code path has existed since approximately 2013 (389-ds-base 1.3.2) and was not addressed by the CVE-2025-14905 fix, which patched a separate heap overflow in schema.c only.
Severe if exploited (CVSS 8.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.6%chance of exploitation in 30 days · 46th percentile
Impact if exploited
8.8CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-11610/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-11610/poc.json
Affected
Products 389 Ds Base Red Hat Directory Server 11.5 E4s For Rhel 8 Red Hat Directory Server 11.7 E4s For Rhel 8 Red Hat Directory Server 11.9 For Rhel 8 Red Hat Directory Server 12.2 E4s For Rhel 9 Red Hat Directory Server 12.4 E4s For Rhel 9 Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 10.0 Extended Update Support Red Hat Enterprise Linux 7 Extended Lifecycle Support Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.4 Extended Update Support Long Life Add On
Weakness (CWE)
- CWE-122: Heap-based Buffer Overflow
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
All CVSS metrics
- HIGH 8.8 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - HIGH 8.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Advisories
- https://access.redhat.com/errata/RHSA-2026:36195
- https://access.redhat.com/errata/RHSA-2026:36196
- https://access.redhat.com/errata/RHSA-2026:36197
- https://access.redhat.com/errata/RHSA-2026:36198
- https://access.redhat.com/errata/RHSA-2026:36200
- https://access.redhat.com/errata/RHSA-2026:36201
- https://access.redhat.com/errata/RHSA-2026:36202
- https://access.redhat.com/errata/RHSA-2026:36204
- https://access.redhat.com/errata/RHSA-2026:36205
- https://access.redhat.com/errata/RHSA-2026:36206
- https://access.redhat.com/errata/RHSA-2026:36208
- https://access.redhat.com/errata/RHSA-2026:36209
- https://access.redhat.com/errata/RHSA-2026:36585
- https://access.redhat.com/errata/RHSA-2026:36641
- https://access.redhat.com/errata/RHSA-2026:36660
- https://access.redhat.com/errata/RHSA-2026:36670
- https://access.redhat.com/errata/RHSA-2026:36671