CVE-2026-85501

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH confidence

Score 5.3 from GitHub Security Advisory published 2026-09-16. a secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 5 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

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

Novel vulnerabilities to launch algorithmic complexity attacks on DNSSEC have been researched under the term 'ReTrap'. These result in degradation of service when malicious zones are used to serve the algorithmic complexity vulnerabilities. NLnet Labs Unbound up to and including 1.26.0 is vulnerable to some of them. TagTrap, where the triple(Zone, Algo, KeyTag) matching mechanism introduces a significant attack vector when resolvers handle malicious responses containing numerous mismatched DNSKEY, RRSIG, and DS record. DelegationTrap, where constructing the chain-of-trust requires iterative validation of DNSKEY and DS records from the root zone downward. For deeply nested domains, this results in significant computational overhead. NsecTrap, where responses with excessive invalid NSEC records compel the resolver to validate each one. AdditionalTrap, where Unbound by default would try to DNSSEC validate the ADDITIONAL section as well. This can be exploited to waste validation resources by malicious users.

CVSS v3
5.3
EG Score
5.3(high)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
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-2026-85501.txt

Vendor Advisories for CVE-2026-85501(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.

All Vendor Advisories

(1)

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 23× in last 7d / 23× 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. 2026-09-20 20:16 UTCEPSS rescore
  2. 2026-09-20 11:47 UTCEG score recompute
  3. 2026-09-20 11:47 UTCVendor advisory
  4. 2026-09-20 11:47 UTCGHSA enrichment
  5. 2026-09-19 13:58 UTCEG score recompute
  6. 2026-09-19 13:58 UTCVendor advisory
  7. 2026-09-19 13:58 UTCGHSA enrichment
  8. 2026-09-18 19:28 UTCEPSS rescore
  9. 2026-09-18 16:07 UTCEG score recompute
  10. 2026-09-18 16:07 UTCVendor advisory
  11. 2026-09-18 16:07 UTCGHSA enrichment
  12. 2026-09-17 19:32 UTCEPSS rescore
  13. 2026-09-17 18:20 UTCVendor advisory
  14. 2026-09-17 18:20 UTCGHSA enrichment
  15. 2026-09-16 19:45 UTCGHSA enrichment
  16. 2026-09-16 15:25 UTCEG score recompute
  17. 2026-09-16 15:25 UTCGHSA enrichment
  18. 2026-09-16 14:26 UTCEG score recompute
  19. 2026-09-16 14:26 UTCGHSA enrichment
  20. 2026-09-16 14:09 UTCEPSS rescore
  21. 2026-09-16 09:30 UTCEG score recompute
  22. 2026-09-16 08:42 UTCEG score recompute
  23. 2026-09-16 08:41 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-85501?
CVE-2026-85501 is a medium vulnerability published on September 16, 2026. Novel vulnerabilities to launch algorithmic complexity attacks on DNSSEC have been researched under the term 'ReTrap'. These result in degradation of service when malicious zones are used to serve the algorithmic complexity vulnerabilities. NLnet Labs Unbound up to and including 1.26.0 is…
When was CVE-2026-85501 disclosed?
CVE-2026-85501 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-2026-85501 actively exploited?
CVE-2026-85501 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 75.7% of all scored CVEs.
What is the CVSS score of CVE-2026-85501?
CVE-2026-85501 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-85501?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-85501, 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

Explore the affected products and dependency analysis for CVE-2026-85501

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