CVE-2023-39976

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2023-08-08. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

log_blackbox.c in libqb before 2.0.8 allows a buffer overflow via long log messages because the header size is not considered.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
59(Track)
EG Risk 59/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
66%
KEV
Not listed

Published

August 8, 2023

Last Modified

November 21, 2024

Advisory Details (4)

Auto-updated Sep 18, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
generic

[SECURITY] Fedora 38 Update: libqb-2.0.8-1.fc38 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KECNF7LFBPE57XSBT6EM7ACVMIBP63WH/
github_pr

log: fix potential overflow with long log messages

Fix merged in ClusterLabs/libqb PR #490 on 2023-07-20 — awaiting tagged release

https://github.com/ClusterLabs/libqb/pull/490
generic

Comparing v2.0.7...v2.0.8 · ClusterLabs/libqb · GitHub

https://github.com/ClusterLabs/libqb/compare/v2.0.7...v2.0.8
github_commit

commit 1bbaa929b771 (ClusterLabs/libqb)

Fix landed in ClusterLabs/libqb commit 1bbaa929b771 — awaiting tagged release

https://github.com/ClusterLabs/libqb/commit/1bbaa929b77113532785c408dd1b41cd0521ffc8

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibqb100 (2.0.4-1ubuntu0.2) @ jammy2026-05-24ubuntu
redhatlibqb-0:2.0.6-3.el9_22023-11-21redhat
redhatlibqb-0:2.0.6-4.el9_32023-11-07redhat
redhatlibqb-0:2.0.3-12.el9_02023-10-10redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
libqb2.0.3-1 ... 2.0.9-1 (8 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
libqb2.0.6-2, 2.0.7-1, 2.0.8-1, 2.0.8-2, 2.0.9-1——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
libqb—2.0.8-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
libqb—2.0.8-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(5)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 7× in last 7d / 29× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 183 total refreshes for this CVE.

  1. 2026-09-24 14:01 UTCEPSS rescore
  2. 2026-09-24 14:01 UTCEPSS rescore
  3. 2026-09-23 13:46 UTCEPSS rescore
  4. 2026-09-23 03:02 UTCOSV refresh
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  23. 2026-09-03 21:59 UTCOSV refresh
  24. 2026-09-02 14:09 UTCEPSS rescore
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  1. 2026-08-30 19:15 UTCEPSS rescore
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  30. 2026-08-03 10:34 UTCEPSS rescore
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  49. 2026-07-23 02:25 UTCEG score recompute
  50. 2026-07-22 23:12 UTCEG score recompute
  51. 2026-07-22 14:06 UTCEPSS rescore
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Related CVEs(same product + same CWE)

Same product

1 shown

Debian:11:libqb

Frequently asked(5)

What is CVE-2023-39976?
CVE-2023-39976 is a critical vulnerability published on August 8, 2023. log_blackbox.c in libqb before 2.0.8 allows a buffer overflow via long log messages because the header size is not considered.
When was CVE-2023-39976 disclosed?
CVE-2023-39976 was first published in the National Vulnerability Database on August 8, 2023, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-39976 actively exploited?
CVE-2023-39976 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 33.6% of all scored CVEs.
What is the CVSS score of CVE-2023-39976?
CVE-2023-39976 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2023-39976?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-39976, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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