--- id: CVE-2026-11610 title: >- 389-ds-base: 389-ds-base: heap buffer overflow in sasl_io_recv() via padded sasl unbind summary: >- A 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 UN… severity: high cvss: 8.8 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H' cvssSource: cna cwe: - CWE-122 vendor: 389ds product: 389-ds-base affected: - 389-ds-base >= 1.3.2 <= 3.3.0 - 'redhat-ds:11 (all versions)' - 'redhat-ds:11 (all versions)' - 'redhat-ds:11 (all versions)' - 'redhat-ds:12 (all versions)' - 'redhat-ds:12 (all versions)' - 389-ds-base (all versions) - 389-ds-base (all versions) - 389-ds-base (all versions) - '389-ds:1.4 (all versions)' - '389-ds:1.4 (all versions)' - '389-ds:1.4 (all versions)' - '389-ds:1.4 (all versions)' - '389-ds:1.4 (all versions)' - '389-ds:1.4 (all versions)' - '389-ds:1.4 (all versions)' - 389-ds-base (all versions) - 389-ds-base (all versions) - 389-ds-base (all versions) - 389-ds-base (all versions) - dirsrv/dirsrv-container-rhel10 (all versions) - 'redhat-ds:12/389-ds-base (all versions)' - 389-ds-base - 389-ds-base (all versions) ssvc: exploitation: none automatable: 'no' technicalImpact: total timestamp: '2026-07-08T21:02:20.457715Z' published: '2026-07-07' updated: '2026-11-04' sourceUpdated: '2026-11-04T21:50:54.575Z' source: CVEORG sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-11610' references: - url: 'https://access.redhat.com/errata/RHSA-2026:36195' label: 'RHSA-2026:36195' - url: 'https://access.redhat.com/errata/RHSA-2026:36196' label: 'RHSA-2026:36196' - url: 'https://access.redhat.com/errata/RHSA-2026:36197' label: 'RHSA-2026:36197' - url: 'https://access.redhat.com/errata/RHSA-2026:36198' label: 'RHSA-2026:36198' - url: 'https://access.redhat.com/errata/RHSA-2026:36200' label: 'RHSA-2026:36200' - url: 'https://access.redhat.com/errata/RHSA-2026:36201' label: 'RHSA-2026:36201' - url: 'https://access.redhat.com/errata/RHSA-2026:36202' label: 'RHSA-2026:36202' - url: 'https://access.redhat.com/errata/RHSA-2026:36204' label: 'RHSA-2026:36204' - url: 'https://access.redhat.com/errata/RHSA-2026:36205' label: 'RHSA-2026:36205' - url: 'https://access.redhat.com/errata/RHSA-2026:36206' label: 'RHSA-2026:36206' - url: 'https://access.redhat.com/errata/RHSA-2026:36208' label: 'RHSA-2026:36208' - url: 'https://access.redhat.com/errata/RHSA-2026:36209' label: 'RHSA-2026:36209' - url: 'https://access.redhat.com/errata/RHSA-2026:36585' label: 'RHSA-2026:36585' - url: 'https://access.redhat.com/errata/RHSA-2026:36641' label: 'RHSA-2026:36641' - url: 'https://access.redhat.com/errata/RHSA-2026:36660' label: 'RHSA-2026:36660' - url: 'https://access.redhat.com/errata/RHSA-2026:36670' label: 'RHSA-2026:36670' - url: 'https://access.redhat.com/errata/RHSA-2026:36671' label: 'RHSA-2026:36671' - url: 'https://access.redhat.com/security/cve/CVE-2026-11610' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2484414' label: RHBZ#2484414 tags: - cve.org epss: 0.00486 epssPercentile: 0.42009 ingestedAt: '2026-11-05T21:36:00.625Z' --- ## Overview A 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. ## Affected - `389-ds-base >= 1.3.2 <= 3.3.0` - `redhat-ds:11 (all versions)` - `redhat-ds:11 (all versions)` - `redhat-ds:11 (all versions)` - `redhat-ds:12 (all versions)` - `redhat-ds:12 (all versions)` - `389-ds-base (all versions)` - `389-ds-base (all versions)` - `389-ds-base (all versions)` - `389-ds:1.4 (all versions)` - `389-ds:1.4 (all versions)` - `389-ds:1.4 (all versions)` - `389-ds:1.4 (all versions)` - `389-ds:1.4 (all versions)` - `389-ds:1.4 (all versions)` - `389-ds:1.4 (all versions)` - `389-ds-base (all versions)` - `389-ds-base (all versions)` - `389-ds-base (all versions)` - `389-ds-base (all versions)` - `dirsrv/dirsrv-container-rhel10 (all versions)` - `redhat-ds:12/389-ds-base (all versions)` - `389-ds-base` - `389-ds-base (all versions)` ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ### Workarounds There is no complete workaround for this flaw. Mitigations that reduce exposure: 1. Restrict network access to LDAP ports (389/636) to trusted networks only. Note: In FreeIPA/IdM deployments, enrolled clients require LDAP access and this may not be practical. 2. If DIGEST-MD5 is not required, disable it via nsslapd-allowed-sasl-mechanisms in cn=config. GSSAPI/Kerberos cannot be disabled in FreeIPA/IdM without breaking domain authentication. 3. Monitor for oversized LDAP UNBIND packets (standard UNBIND is 7 bytes; alert on UNBIND packets exceeding ~100 bytes). 4. Lowering nsslapd-maxbersize reduces maximum overflow size but does not eliminate the vulnerability.