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: 0.6%CVSS: 9.8Exploit: None knownExposed services: Not assessed

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
9.8CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
EPSS PROB
0.6%
EPSS %ILE
45th
KEV
Not listed

Published

March 6, 2026

Last Modified

September 10, 2026

Advisory Details (10)

Auto-updated Oct 1, 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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
python-authlib1.6.0-1 ... 1.7.2-2 (13 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
python-authlib1.6.0-1 ... 1.6.6-1 (6 versions)
  • every version up to 1.6.7-1: fixed in 1.6.7-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
authlib1.6.5, 1.6.6
  • 1.6.5 up to 1.6.7: fixed in 1.6.7
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 27× 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 161 total refreshes for this CVE.

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

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

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 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 0.6% probability of exploitation in the next 30 days (45th percentile of EPSS-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?
A fix for CVE-2026-28802 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-28802 are linked in the Vendor Advisories panel on this page.

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