CVE-2026-26999

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 57% 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
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.38 and 3.6.9, there is a potential vulnerability in Traefik managing TLS handshake on TCP routers. When Traefik processes a TLS connection on a TCP router, the read deadline used to bound protocol sniffing is cleared before the TLS handshake is completed. When a TLS handshake read error occurs, the code attempts a second handshake with different connection parameters, silently ignoring the initial error. A remote unauthenticated client can exploit this by sending an incomplete TLS record and stopping further data transmission, causing the TLS handshake to stall indefinitely and holding connections open. By opening many such stalled connections in parallel, an attacker can exhaust file descriptors and goroutines, degrading availability of all services on the affected entrypoint. This issue has been patched in versions 2.11.38 and 3.6.9.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

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
Severity75% × 45%
Exploitation1% × 40%
Automatability100% × 15%
EPSS PROB
0.7%
EPSS %ILE
52nd
KEV
Not listed

Published

March 5, 2026

Last Modified

July 15, 2026

Advisory Details (7)

Auto-updated Jul 3, 2026
🔬 Proof of concept available. Patch available. Sources: github, redhat, github_release.
redhatMentions a patch (unverified)
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26999.json
redhat

2444874 – (CVE-2026-26999) CVE-2026-26999 github.com/traefik/traefik: Traefik: Denial of Service due to incomplete TLS handshake

https://bugzilla.redhat.com/show_bug.cgi?id=2444874
redhatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/CVE-2026-26999
redhatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:10175
githubMentions a patch (unverified)🟡 PoC Available

TLS Handshake Error Handling Allows Stalled Connections on TCP Routers · Advisory · traefik/traefik · GitHub

https://github.com/traefik/traefik/security/advisories/GHSA-xw98-5q62-jx94
github_release Patch Available

v3.6.9

Patch available: traefik/traefik v3.6.9

https://github.com/traefik/traefik/releases/tag/v3.6.9
github_release Patch Available

v2.11.38

Patch available: traefik/traefik v2.11.38

https://github.com/traefik/traefik/releases/tag/v2.11.38

Vendor Advisories for CVE-2026-26999(1)

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 / EcosystemFix (by version range) / PatchReleasedSource
redhatdevspaces/traefik-rhel9:17767185852026-04-23redhat

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.

Affected Packages

(3 across 1 ecosystem)
Go(3)
PackageVulnerable rangeFix by version rangeDependents
github.com/traefik/traefik—
  • every version on: no fix on record
—
github.com/traefik/traefik/v2—
  • every version up to 2.11.38: fixed in 2.11.38
—
github.com/traefik/traefik/v3—
  • every version up to 3.6.9: fixed in 3.6.9
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 24× 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 138 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-26999?
CVE-2026-26999 is a high vulnerability published on March 5, 2026. Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.38 and 3.6.9, there is a potential vulnerability in Traefik managing TLS handshake on TCP routers. When Traefik processes a TLS connection on a TCP router, the read deadline used to bound protocol sniffing is cleared before…
When was CVE-2026-26999 disclosed?
CVE-2026-26999 was first published on March 5, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-26999 actively exploited?
CVE-2026-26999 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (52nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-26999?
CVE-2026-26999 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-26999?
A fix for CVE-2026-26999 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-26999 are linked in the Vendor Advisories panel on this page.

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