CVE-2026-12528
A malformed ACI (Access Control Instruction) string can trigger heap-buffer-overflow writes and reads during ACI parsing.
Does this matter?
Lower severity and a low EPSS score (0.23%). Track it; it rarely justifies an emergency change on its own.
Description
A flaw was found in 389 Directory Server in the __aclp__normalize_acltxt() function of aclparse.c. A malformed ACI (Access Control Instruction) string can trigger heap-buffer-overflow writes and reads during ACI parsing. The function fails to validate that the ACI keyword has sufficient length after whitespace stripping, leading to a 1-byte out-of-bounds write and subsequent out-of-bounds reads. An authenticated user with write access to the aci attribute could send a crafted ACI value to silently corrupt heap memory in the directory server process.
- CVSS 3.1
- 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
- EPSS
- 0.23% probability · 13th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- redhat/directory server · redhat/389 directory server · redhat/enterprise linux
- Source
- secalert@redhat.com
References
- https://access.redhat.com/security/cve/CVE-2026-12528Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2489835Issue Tracking, Vendor Advisory
- https://github.com/389ds/389-ds-base/pull/7542Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.