CVE-2026-38821

HIGHPre-NVD 7.17.1—
EchelonGraph scoreHIGH confidence

Score 7.1 from GitHub Security Advisory (severity: HIGH) published 2026-08-28. a secondary CVSS source baseline 7.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.1Exploit: None knownExposed: 0

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

A heap-based buffer overflow vulnerability exists in openNDS before 11.0.0 that allows an unauthenticated attacker on the captive portal network to crash the openNDS daemon (denial of service) and potentially achieve remote code execution. This is in http_microhttpd.c.

CVSS v3
7.1
EG Score
7.1(high)
EG Risk
32(Track)
EG Risk 32/100SSVC: 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
Severity71% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
10%
KEV
Not listed

Published

August 28, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated Aug 28, 2026
Patch available. Sources: github_commit.
github_commit Patch Available

commit 3b5f7ef40cd0 (openNDS/openNDS)

Patch available: openNDS/openNDS v11.0.0 (contains commit 3b5f7ef40cd0)

https://github.com/openNDS/openNDS/commit/3b5f7ef40cd048826d3c4a16f61a73a1768fd5a9

Vendor Advisories for CVE-2026-38821(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 14× in last 7d / 14× 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. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 19:50 UTCGHSA enrichment
  3. 2026-08-29 08:05 UTCEG score recompute
  4. 2026-08-29 08:05 UTCGHSA enrichment
  5. 2026-08-28 21:41 UTCEPSS rescore
  6. 2026-08-28 20:22 UTCEG score recompute
  7. 2026-08-28 20:22 UTCGHSA enrichment
  8. 2026-08-28 19:45 UTCEG score recompute
  9. 2026-08-28 19:45 UTCGHSA enrichment
  10. 2026-08-28 14:00 UTCEG score recompute
  11. 2026-08-28 14:00 UTCGHSA enrichment
  12. 2026-08-28 02:18 UTCEG score recompute
  13. 2026-08-28 02:10 UTCEG score recompute
  14. 2026-08-28 02:07 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-38821?
CVE-2026-38821 is a high vulnerability published on August 28, 2026. A heap-based buffer overflow vulnerability exists in openNDS before 11.0.0 that allows an unauthenticated attacker on the captive portal network to crash the openNDS daemon (denial of service) and potentially achieve remote code execution. This is in http_microhttpd.c.
When was CVE-2026-38821 disclosed?
CVE-2026-38821 was first published in the National Vulnerability Database on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-38821 actively exploited?
CVE-2026-38821 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 90.0% of all scored CVEs.
What is the CVSS score of CVE-2026-38821?
CVE-2026-38821 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-38821?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-38821, 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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