CVE-2026-28802

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 64% 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, nvd
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.. This issue has been patched in version 1.6.7.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

March 6, 2026

Last Modified

September 10, 2026

Advisory Details (10)

Auto-updated Sep 17, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github, redhat.
redhat Patch Available

CVE-2026-28802 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-28802
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:6568
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:6309
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:5665
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:5168
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:4942
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:19375
github Patch Available🟡 PoC Available

Setting `alg: none` and a blank signature appears to bypass signature verification · Advisory · authlib/authlib · GitHub

https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg
github_commit Patch Available

commit b87c32ed07b8 (authlib/authlib)

Patch available: authlib/authlib v1.6.7 (contains commit b87c32ed07b8)

https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7
github_commit Patch Available

commit a61c2acb8074 (authlib/authlib)

Patch available: authlib/authlib v1.6.0 (contains commit a61c2acb8074)

https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75

Vendor Advisories for CVE-2026-28802(7)

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

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatquay/quay-rhel9:17792040862026-05-19redhat
redhatquay/quay-rhel8:17751692192026-04-03redhat
redhatansible-automation-platform-26/lightspeed-chatbot-rhel9:17744170222026-04-01redhat
redhatquay/quay-rhel8:17739710772026-03-24redhat
redhatquay/quay-rhel8:17739363232026-03-19redhat
redhatquay/quay-rhel8:17737719622026-03-18redhat

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 3 ecosystems)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
python-authlib1.6.0-1 ... 1.7.2-2 (13 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
python-authlib1.6.0-1 ... 1.6.6-1 (6 versions)1.6.7-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
authlib1.6.5, 1.6.61.6.7—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 33× 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 150 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-28802?
CVE-2026-28802 is a critical vulnerability published on March 6, 2026. Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code…
When was CVE-2026-28802 disclosed?
CVE-2026-28802 was first published in the National Vulnerability Database on March 6, 2026, with the most recent update on September 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-28802 actively exploited?
CVE-2026-28802 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 63.6% of all scored CVEs.
What is the CVSS score of CVE-2026-28802?
CVE-2026-28802 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-28802?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-28802, 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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