Vulnerability in 389-ds-base
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as UBUNTU-CVE-2026-18355 has been found in 389-ds-base.
Successful exploitation can lead to full system takeover.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "389-ds-base UBUNTU-CVE-2026-18355" on the vendor's site.
UBUNTU-CVE-2026-18355 (389-ds-base)
Attack vector: remote (network-reachable) / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in 389-ds-base.
Check the vendor advisory for the affected versions of 389-ds-base.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '389-ds-base' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1
Identify exposureidentify
grep -r '389-ds-base' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
389-ds-baseを grep し、稼働しているサービス・バージョンを把握する。 -
2
Post-deployment verificationverify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
| Package | Affected → Fixed | |
|---|---|---|
| Ubuntu:Pro:16.04:LTS389-ds-base |
All versions→ Not listed |
Not listed |
| Ubuntu:Pro:18.04:LTS389-ds-base |
All versions→ Not listed |
Not listed |
| Ubuntu:Pro:20.04:LTS389-ds-base |
All versions→ Not listed |
Not listed |
| Ubuntu:22.04:LTS389-ds-base |
All versions→ Not listed |
Not listed |
| Ubuntu:24.04:LTS389-ds-base |
All versions→ Not listed |
Not listed |
| Ubuntu:26.10389-ds-base |
All versions→ Not listed |
Not listed |
| Ubuntu:26.04:LTS389-ds-base |
All versions→ Not listed |
Not listed |
This record does not list fixed versions. Check the article or the vendor advisory in the references for whether and where it is fixed.
Original description The description as published by the source.
A heap buffer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), the wrapped-record length read from the wire is validated only against an upper bound. A small wire length (0, 1, or 2) produces an encrypted_buffer_count below the already-consumed encrypted_buffer_offset, causing an unsigned subtraction underflow in sasl_io_read_packet(). PR_Recv is then requested to read approximately 4 GiB into a 1024-byte heap buffer, resulting in a heap buffer overflow with attacker-controlled content. After a successful SASL bind with integrity protection (SSF > 0), a remote authenticated attacker can cause a denial of service or potentially achieve remote code execution. This flaw is distinct from CVE-2026-11774, whose fix only guards against upper-bound overflow.
Source: OSV.dev (Open Source Vulnerabilities) OSV
References
- report ubuntu.com
- report cve.org
- report bugzilla.redhat.com