CVE-2026-28368

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.7%, top 50% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.1Exploit: None knownExposed: 0

A fix is available — apply it.

A flaw was found in Undertow. This vulnerability allows a remote attacker to construct specially crafted requests where header names are parsed differently by Undertow compared to upstream proxies. This discrepancy in header interpretation can be exploited to launch request smuggling attacks, potentially bypassing security controls and accessing unauthorized resources.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: 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
Severity91% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
51%
KEV
Not listed

Published

March 27, 2026

Last Modified

June 29, 2026

Advisory Details (4)

Auto-updated Aug 1, 2026
Patch available. Sources: redhat.
redhat Patch Available

2443261 – (CVE-2026-28368) CVE-2026-28368 undertow: Undertow: Request smuggling via inconsistent header parsing

https://bugzilla.redhat.com/show_bug.cgi?id=2443261
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-28368
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:25126
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:25125

Vendor Advisories for CVE-2026-28368(3)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatundertow-core2026-06-10redhat
redhateap8-wildfly-0:8.1.6-7.GA_redhat_00010.1.el9eap2026-06-10redhat
mavenio.undertow:undertow-parent—ghsa

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

(2 across 2 ecosystems)
Debian:14(1)
PackageVulnerable rangeFixed inDependents
undertow1.3.11-1 ... 2.3.8-2 (56 versions)——
Maven(1)
PackageVulnerable rangeFixed inDependents
io.undertow:undertow-parent1.0.0.Alpha1 ... 2.3.9.Final (335 versions)——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 117× 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 187 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-28368?
CVE-2026-28368 is a critical vulnerability published on March 27, 2026. A flaw was found in Undertow. This vulnerability allows a remote attacker to construct specially crafted requests where header names are parsed differently by Undertow compared to upstream proxies. This discrepancy in header interpretation can be exploited to launch request smuggling attacks,…
When was CVE-2026-28368 disclosed?
CVE-2026-28368 was first published in the National Vulnerability Database on March 27, 2026, with the most recent update on June 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-28368 actively exploited?
CVE-2026-28368 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 49.4% of all scored CVEs.
What is the CVSS score of CVE-2026-28368?
CVE-2026-28368 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-28368?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-28368, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-28368

Explore →

Is Your Infrastructure Affected by CVE-2026-28368?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs