CVE-2026-77955

MEDIUMPre-NVD 4.44.4—
EchelonGraph scoreHIGH confidence

Score 4.4 from GitHub Security Advisory published 2026-09-16. a secondary CVSS source baseline 4.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
4.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

In NLnet Labs Unbound 1.13.2 up to and including 1.26.1, a vulnerability in ZONEMD configured zones (zonemd-check: yes) which are located below (but not at) a trust anchor allow for an attack window where (tampered with) zone contents are served (or stored to disk) prior to the ZONEMD integrity check. This is caused by the needed DS/DNSKEY asynchronous resolution that needs to happen before the ZONEMD check completes. If a zonefile is written to disk (zonefile: option) while the ZONEMD check failed, the tampered data are reloaded on startup and available until ZONEMD verification concludes again. If verification fails, the data is not served any more but still persists on disk for future reloads.

CVSS v3
4.4
EG Score
4.4(high)
EG Risk
20(Track)
EG Risk 20/100SSVC: 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
Severity44% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
3%
KEV
Not listed

Published

September 16, 2026

Last Modified

September 16, 2026

Advisory Details (1)

Auto-updated Sep 16, 2026
No patch confirmed yet.
generic
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-77955.txt

Vendor Advisories for CVE-2026-77955(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 15× 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.

  1. 2026-09-19 15:54 UTCEG score recompute
  2. 2026-09-19 15:53 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 17:09 UTCGHSA enrichment
  5. 2026-09-17 18:28 UTCGHSA enrichment
  6. 2026-09-16 19:45 UTCGHSA enrichment
  7. 2026-09-16 15:25 UTCEG score recompute
  8. 2026-09-16 15:25 UTCGHSA enrichment
  9. 2026-09-16 14:51 UTCEG score recompute
  10. 2026-09-16 14:51 UTCGHSA enrichment
  11. 2026-09-16 14:08 UTCEPSS rescore
  12. 2026-09-16 09:31 UTCEG score recompute
  13. 2026-09-16 09:31 UTCGHSA enrichment
  14. 2026-09-16 08:42 UTCEG score recompute
  15. 2026-09-16 08:41 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-77955?
CVE-2026-77955 is a medium vulnerability published on September 16, 2026. In NLnet Labs Unbound 1.13.2 up to and including 1.26.1, a vulnerability in ZONEMD configured zones (zonemd-check: yes) which are located below (but not at) a trust anchor allow for an attack window where (tampered with) zone contents are served (or stored to disk) prior to the ZONEMD integrity…
When was CVE-2026-77955 disclosed?
CVE-2026-77955 was first published in the National Vulnerability Database on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77955 actively exploited?
CVE-2026-77955 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 97.1% of all scored CVEs.
What is the CVSS score of CVE-2026-77955?
CVE-2026-77955 has a CVSS v3 base score of 4.4 (NVD).
How do I remediate CVE-2026-77955?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77955, 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.

Dependency Blast Radius

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