CVE-2026-42530

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-17. a secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
8.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 3%CVSS: 8.1Exploit: NoneExposed: 0

A fix is available — apply it.

NGINX Open Source has a vulnerability in the ngx_http_v3_module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This may cause a Use-after-Free in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
52(Track)
EG Risk 52/100SSVC: 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
Severity81% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
86.9%
KEV
Not listed

Published

June 17, 2026

Last Modified

July 16, 2026

Advisory Details (1)

Auto-updated Jun 18, 2026
No patch confirmed yet.
generic

myF5

https://my.f5.com/manage/s/article/K000161616

Vendor Advisories for CVE-2026-42530(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatnginx-main-1.30.2-1.hum12026-05-23redhat

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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 80× 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 101 total refreshes for this CVE.

  1. 2026-07-23 03:11 UTCEG score recompute
  2. 2026-07-22 14:08 UTCEPSS rescore
  3. 2026-07-21 15:24 UTCEPSS rescore
  4. 2026-07-20 17:08 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:29 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-17 01:45 UTCVendor advisory
  9. 2026-07-17 01:45 UTCGHSA enrichment
  10. 2026-07-16 17:03 UTCEPSS rescore
  11. 2026-07-16 13:37 UTCVendor advisory
  12. 2026-07-16 13:37 UTCGHSA enrichment
  13. 2026-07-16 01:19 UTCVendor advisory
  14. 2026-07-16 01:19 UTCGHSA enrichment
  15. 2026-07-15 16:57 UTCEPSS rescore
  16. 2026-07-15 13:14 UTCGHSA enrichment
  17. 2026-07-14 22:27 UTCGHSA enrichment
  18. 2026-07-14 10:07 UTCGHSA enrichment
  19. 2026-07-13 22:30 UTCEPSS rescore
  20. 2026-07-13 21:49 UTCGHSA enrichment
  21. 2026-07-13 09:42 UTCGHSA enrichment
  22. 2026-07-13 06:13 UTCEPSS rescore
  23. 2026-07-12 21:37 UTCGHSA enrichment
  24. 2026-07-12 09:17 UTCGHSA enrichment
  25. 2026-07-12 05:46 UTCEPSS rescore
Show 75 more
  1. 2026-07-11 21:11 UTCGHSA enrichment
  2. 2026-07-11 09:06 UTCGHSA enrichment
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-10 20:59 UTCGHSA enrichment
  5. 2026-07-10 08:54 UTCGHSA enrichment
  6. 2026-07-09 20:48 UTCGHSA enrichment
  7. 2026-07-09 19:10 UTCEPSS rescore
  8. 2026-07-09 08:38 UTCGHSA enrichment
  9. 2026-07-08 20:26 UTCGHSA enrichment
  10. 2026-07-08 15:15 UTCEPSS rescore
  11. 2026-07-08 08:12 UTCGHSA enrichment
  12. 2026-07-07 20:05 UTCGHSA enrichment
  13. 2026-07-07 13:46 UTCEPSS rescore
  14. 2026-07-07 02:20 UTCGHSA enrichment
  15. 2026-07-06 16:27 UTCEPSS rescore
  16. 2026-07-06 16:27 UTCEPSS rescore
  17. 2026-07-06 13:55 UTCGHSA enrichment
  18. 2026-07-06 02:23 UTCEPSS rescore
  19. 2026-07-06 02:23 UTCEPSS rescore
  20. 2026-07-06 01:37 UTCGHSA enrichment
  21. 2026-07-05 13:31 UTCGHSA enrichment
  22. 2026-07-05 02:30 UTCEPSS rescore
  23. 2026-07-05 01:26 UTCGHSA enrichment
  24. 2026-07-04 13:20 UTCGHSA enrichment
  25. 2026-07-04 06:31 UTCEPSS rescore
  26. 2026-07-04 01:14 UTCGHSA enrichment
  27. 2026-07-03 13:08 UTCGHSA enrichment
  28. 2026-07-03 00:46 UTCGHSA enrichment
  29. 2026-07-02 12:40 UTCGHSA enrichment
  30. 2026-07-02 00:34 UTCGHSA enrichment
  31. 2026-07-01 15:06 UTCEPSS rescore
  32. 2026-07-01 12:29 UTCGHSA enrichment
  33. 2026-07-01 00:23 UTCGHSA enrichment
  34. 2026-06-30 23:22 UTCEPSS rescore
  35. 2026-06-30 12:16 UTCGHSA enrichment
  36. 2026-06-30 00:09 UTCGHSA enrichment
  37. 2026-06-29 12:04 UTCGHSA enrichment
  38. 2026-06-28 23:58 UTCGHSA enrichment
  39. 2026-06-28 14:07 UTCEPSS rescore
  40. 2026-06-28 11:52 UTCGHSA enrichment
  41. 2026-06-28 04:56 UTCEPSS rescore
  42. 2026-06-27 23:47 UTCGHSA enrichment
  43. 2026-06-27 11:42 UTCGHSA enrichment
  44. 2026-06-27 03:08 UTCEPSS rescore
  45. 2026-06-26 23:36 UTCGHSA enrichment
  46. 2026-06-26 11:31 UTCGHSA enrichment
  47. 2026-06-25 19:43 UTCGHSA enrichment
  48. 2026-06-25 13:49 UTCEPSS rescore
  49. 2026-06-25 13:49 UTCEPSS rescore
  50. 2026-06-25 07:37 UTCGHSA enrichment
  51. 2026-06-24 19:32 UTCGHSA enrichment
  52. 2026-06-24 14:05 UTCEPSS rescore
  53. 2026-06-24 05:41 UTCGHSA enrichment
  54. 2026-06-23 21:33 UTCEPSS rescore
  55. 2026-06-23 17:25 UTCGHSA enrichment
  56. 2026-06-23 05:12 UTCGHSA enrichment
  57. 2026-06-22 16:56 UTCGHSA enrichment
  58. 2026-06-22 14:25 UTCEPSS rescore
  59. 2026-06-22 14:25 UTCEPSS rescore
  60. 2026-06-22 04:50 UTCGHSA enrichment
  61. 2026-06-21 16:44 UTCGHSA enrichment
  62. 2026-06-21 14:56 UTCEPSS rescore
  63. 2026-06-21 14:56 UTCEPSS rescore
  64. 2026-06-21 04:39 UTCGHSA enrichment
  65. 2026-06-21 01:59 UTCEPSS rescore
  66. 2026-06-20 16:33 UTCGHSA enrichment
  67. 2026-06-20 04:26 UTCGHSA enrichment
  68. 2026-06-19 19:25 UTCEPSS rescore
  69. 2026-06-19 16:18 UTCGHSA enrichment
  70. 2026-06-19 04:11 UTCGHSA enrichment
  71. 2026-06-18 17:52 UTCEPSS rescore
  72. 2026-06-18 17:52 UTCEPSS rescore
  73. 2026-06-18 16:04 UTCGHSA enrichment
  74. 2026-06-18 03:58 UTCGHSA enrichment
  75. 2026-06-17 15:53 UTCEG score recompute

Publicly available exploits

(2 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCv4ltonn/CVE-2026-42530
    First seen Jun 19, 2026

    Scanner PoC for CVE-2026-42530 -- nginx 1.31.0-1.31.1 HTTP/3 QPACK encoder stream Use-After-Free (CVSS 9.2)

    Open source ↗
  • GitHub PoC0xBlackash/CVE-2026-42530
    First seen Jun 19, 2026

    CVE-2026-42530

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-42530?
CVE-2026-42530 is a high vulnerability published on June 17, 2026. NGINX Open Source has a vulnerability in the ngxhttpv3_module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This…
When was CVE-2026-42530 disclosed?
CVE-2026-42530 was first published in the National Vulnerability Database on June 17, 2026, with the most recent update on July 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42530 actively exploited?
CVE-2026-42530 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 86.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42530?
CVE-2026-42530 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-42530?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42530, 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-2026-42530

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