PatchTheCVECVE-2026-12528: A flaw was found in 389 Directory Server in the __aclp__normalize_acltxt() function of aclparse.c
CVE-2026-12528 is a medium-severity flaw (CVSS 5.4) affecting directory server, 389 directory server, enterprise linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- On your watchlist
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 5.4 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.2% (top 87%) |
| CISA exploited list | No |
| Weakness | CWE-787 |
| Published | 2026-06-17 |
| Last modified | 2026-06-28 |
Last updated 2026-06-28 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-12528?
directory server: downgrade or apply the listed mitigation; 389 directory server: mitigate or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2026-12528 being exploited?
CVE-2026-12528 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-12528 affect?
CVE-2026-12528 affects directory server, 389 directory server, enterprise linux. Severity is medium (CVSS 5.4). 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
How urgent is CVE-2026-12528?
Priority 27/100. On your watchlist
Related CVEs
- CVE-2026-15722 HIGH 7.5 DOWNGRADE MITIGATE A stack buffer overflow flaw was found in 389 Directory Server (389-ds-base)
- CVE-2026-11770 HIGH 7.5 DOWNGRADE MITIGATE A flaw was found in 389 Directory Server
- CVE-2026-18651 MEDIUM 5.4 DOWNGRADE MITIGATE A flaw was found in 389 Directory Server
- CVE-2026-11611 MEDIUM 6.5 DOWNGRADE MITIGATE A flaw was found in 389 Directory Server
- CVE-2026-14940 MEDIUM 5.3 DOWNGRADE MITIGATE A heap-buffer-overflow flaw was found in 389 Directory Server (389-ds-base)