CVE-2026-33630

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 61% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

c-ares is an asynchronous resolver library. From ver 1.32.3 until 1.34.7, a use-after-free / double-free in c-ares' query-completion handling. The same flaw — a query's callback being invoked while the query is still linked in the channel's internal lookup structures — is present at multiple points in the resend/finish path (timeout handling, response handling, and query dispatch). If the query, or for ares_getaddrinfo() the owning host_query, is freed as a side effect of that callback, it is then accessed and/or freed a second time. This vulnerability is fixed in ver 1.34.7.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

September 3, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Sep 3, 2026
Patch available. Sources: github_release, github, github_commit.
github_release Patch Available

1.34.7

Patch available: c-ares/c-ares v1.34.7

https://github.com/c-ares/c-ares/releases/tag/v1.34.7
github_commit Patch Available

commit d823199b6880 (c-ares/c-ares)

Patch available: c-ares/c-ares v1.34.7 (contains commit d823199b6880)

https://github.com/c-ares/c-ares/commit/d823199b688052dcdc1646f2ab4cb8c16b1c644a
github Patch Available

Use-after-free / double-free in c-ares query-completion handling, remotely triggerable via ares_getaddrinfo() over TCP · Advisory · c-ares/c-ares · GitHub

https://github.com/c-ares/c-ares/security/advisories/GHSA-6wfj-rwm7-3542

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatc-ares-0:1.34.6-2.el10_22026-07-20redhat
redhatc-ares-main-1.34.7-1.hum12026-07-07redhat

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

(6 across 6 ecosystems)
Alpine:v3.21(1)
PackageVulnerable rangeFixed inDependents
c-ares1.34.8-r0
Alpine:v3.22(1)
PackageVulnerable rangeFixed inDependents
c-ares1.34.8-r0
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
c-ares1.34.8-r0
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
c-ares1.34.8-r0
Debian:13(1)
PackageVulnerable rangeFixed inDependents
c-ares1.34.5-1, 1.34.5-1+deb13u1, 1.34.6-1, 1.34.7-1, 1.34.8-1
Debian:14(1)
PackageVulnerable rangeFixed inDependents
c-ares1.34.5-1, 1.34.6-11.34.7-1

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 28× in last 7d / 73× 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 21:54 UTCEG score recompute
  2. 2026-09-19 21:54 UTCVendor advisory
  3. 2026-09-19 09:56 UTCVendor advisory
  4. 2026-09-18 21:23 UTCEG score recompute
  5. 2026-09-18 21:23 UTCVendor advisory
  6. 2026-09-18 19:28 UTCEPSS rescore
  7. 2026-09-18 19:28 UTCEPSS rescore
  8. 2026-09-18 09:11 UTCVendor advisory
  9. 2026-09-17 21:14 UTCEG score recompute
  10. 2026-09-17 21:14 UTCVendor advisory
  11. 2026-09-17 19:30 UTCEPSS rescore
  12. 2026-09-17 09:17 UTCVendor advisory
  13. 2026-09-16 21:20 UTCEG score recompute
  14. 2026-09-16 21:20 UTCVendor advisory
  15. 2026-09-16 14:08 UTCEPSS rescore
  16. 2026-09-16 09:03 UTCEG score recompute
  17. 2026-09-16 09:03 UTCVendor advisory
  18. 2026-09-16 05:15 UTCEPSS rescore
  19. 2026-09-15 20:53 UTCVendor advisory
  20. 2026-09-15 08:46 UTCEG score recompute
  21. 2026-09-15 08:46 UTCVendor advisory
  22. 2026-09-15 03:11 UTCEPSS rescore
  23. 2026-09-14 20:48 UTCVendor advisory
  24. 2026-09-14 08:50 UTCVendor advisory
  25. 2026-09-13 20:53 UTCEG score recompute
Show 48 more
  1. 2026-09-13 20:53 UTCVendor advisory
  2. 2026-09-13 16:47 UTCEPSS rescore
  3. 2026-09-13 08:55 UTCVendor advisory
  4. 2026-09-12 20:58 UTCEG score recompute
  5. 2026-09-12 20:58 UTCVendor advisory
  6. 2026-09-12 15:01 UTCEPSS rescore
  7. 2026-09-12 09:00 UTCVendor advisory
  8. 2026-09-11 21:02 UTCEG score recompute
  9. 2026-09-11 21:02 UTCVendor advisory
  10. 2026-09-11 14:53 UTCEPSS rescore
  11. 2026-09-11 09:37 UTCEPSS rescore
  12. 2026-09-11 09:05 UTCVendor advisory
  13. 2026-09-10 21:07 UTCEG score recompute
  14. 2026-09-10 21:07 UTCVendor advisory
  15. 2026-09-10 09:34 UTCEPSS rescore
  16. 2026-09-10 09:09 UTCVendor advisory
  17. 2026-09-09 21:10 UTCVendor advisory
  18. 2026-09-09 11:04 UTCVendor advisory
  19. 2026-09-08 23:06 UTCEG score recompute
  20. 2026-09-08 23:06 UTCVendor advisory
  21. 2026-09-08 22:00 UTCEPSS rescore
  22. 2026-09-08 03:13 UTCEG score recompute
  23. 2026-09-08 03:13 UTCVendor advisory
  24. 2026-09-07 16:01 UTCEPSS rescore
  25. 2026-09-07 15:15 UTCVendor advisory
  26. 2026-09-07 03:18 UTCVendor advisory
  27. 2026-09-06 15:17 UTCEG score recompute
  28. 2026-09-06 15:17 UTCVendor advisory
  29. 2026-09-06 13:47 UTCEPSS rescore
  30. 2026-09-06 03:19 UTCEG score recompute
  31. 2026-09-06 03:19 UTCVendor advisory
  32. 2026-09-05 15:21 UTCVendor advisory
  33. 2026-09-05 03:23 UTCEG score recompute
  34. 2026-09-05 03:23 UTCVendor advisory
  35. 2026-09-05 02:30 UTCEG score recompute
  36. 2026-09-05 02:30 UTCVendor advisory
  37. 2026-09-04 21:20 UTCEG score recompute
  38. 2026-09-04 21:20 UTCVendor advisory
  39. 2026-09-04 09:22 UTCVendor advisory
  40. 2026-09-03 21:21 UTCEG score recompute
  41. 2026-09-03 21:21 UTCVendor advisory
  42. 2026-09-03 20:24 UTCEG score recompute
  43. 2026-09-03 20:24 UTCVendor advisory
  44. 2026-09-03 19:19 UTCEG score recompute
  45. 2026-09-03 19:19 UTCVendor advisory
  46. 2026-09-03 18:54 UTCEG score recompute
  47. 2026-09-03 18:54 UTCVendor advisory
  48. 2026-09-03 18:53 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-33630?
CVE-2026-33630 is a high vulnerability published on September 3, 2026. c-ares is an asynchronous resolver library. From ver 1.32.3 until 1.34.7, a use-after-free / double-free in c-ares' query-completion handling. The same flaw — a query's callback being invoked while the query is still linked in the channel's internal lookup structures — is present at multiple points…
When was CVE-2026-33630 disclosed?
CVE-2026-33630 was first published in the National Vulnerability Database on September 3, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33630 actively exploited?
CVE-2026-33630 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 61.4% of all scored CVEs.
What is the CVSS score of CVE-2026-33630?
CVE-2026-33630 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-33630?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33630, 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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