CVE-2026-42055

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
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 6.5%CVSS: 8.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based buffer overflow 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
8.1HIGHmedium confidence
EG Risk
39
EG Risk 39/100

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%
Exploitation7% × 40%
Automatability0% × 15%
EPSS PROB
6.5%
EPSS %ILE
93rd
KEV
Not listed

Published

June 17, 2026

Last Modified

September 14, 2026

Advisory Details (1)

Auto-updated Jun 18, 2026
Patch available.
generic

myF5

https://my.f5.com/manage/s/article/K000161584

Vendor Advisories for CVE-2026-42055(11)

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

Patch Availability(10)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntunginx-light (1.28.3-2ubuntu1.6) @ resolute2026-09-14ubuntu
redhatrhui5/rhua-tp-rhel9:17872412602026-08-24redhat
redhatdiscovery/discovery-ui-rhel9:17848217502026-07-27redhat
redhatrhui5/rhua-rhel9:17847950762026-07-23redhat
redhatnginx:1.24-8100020260707171317.489197e62026-07-13redhat
redhatnginx:1.26-9080020260707110000.92026-07-08redhat
redhatnginx:1.24-9080020260707164406.92026-07-08redhat
redhatnginx-2:1.20.1-28.el9_8.42026-07-07redhat
redhatnginx-2:1.26.3-6.el10_2.52026-07-07redhat
redhatnginx-main-1.30.3-2.hum12026-06-19redhat

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

(8 across 8 ecosystems)
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
nginx—
  • every version up to 1.26.3-r2: fixed in 1.26.3-r2
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
nginx—
  • every version up to 1.28.3-r4: fixed in 1.28.3-r4
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
nginx—
  • every version up to 1.28.3-r4: fixed in 1.28.3-r4
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
nginx—
  • every version up to 1.30.3-r0: fixed in 1.30.3-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
nginx1.18.0-6.1 ... 1.18.0-6.1+deb11u7 (8 versions)
  • every version up to 1.18.0-6.1+deb11u8: fixed in 1.18.0-6.1+deb11u8
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
nginx1.22.1-9 ... 1.22.1-9+deb12u8 (9 versions)
  • every version up to 1.22.1-9+deb12u9: fixed in 1.22.1-9+deb12u9
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
nginx1.26.3-3 ... 1.26.3-3+deb13u6 (7 versions)
  • every version up to 1.26.3-3+deb13u7: fixed in 1.26.3-3+deb13u7
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
nginx1.26.3-3 ... 1.30.1-4 (24 versions)
  • every version up to 1.30.1-5: fixed in 1.30.1-5
—

Weakness Classification(3)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 5× in last 7d / 32× 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 358 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-42055?
CVE-2026-42055 is a high vulnerability published on June 17, 2026. NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpproxyv2module and ngxhttpgrpcmodule modules. This vulnerability exists when the proxyhttpversion to 2 or grpcpass directives are used to proxy HTTP/2 traffic, the ignoreinvalidheaders directive is set to off, and the…
When was CVE-2026-42055 disclosed?
CVE-2026-42055 was first published on June 17, 2026, with the most recent update on September 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42055 actively exploited?
CVE-2026-42055 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.5% probability of exploitation in the next 30 days (93rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-42055?
CVE-2026-42055 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-42055?
A fix for CVE-2026-42055 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-42055 are linked in the Vendor Advisories panel on this page.

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