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.
CVE-2026-28802
CRITICALNVD 9.89.8
EchelonGraph scoreLOW confidence
This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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: nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0
A fix is available — apply it.
- CVSS v3
- 9.8
- EG Score
- 9.8(low)
- EPSS
- 34.2%
- KEV
- Not listed
Published
March 6, 2026
Last Modified
July 1, 2026
Advisory Details (10)
Auto-updated Jul 3, 2026🔬 Proof of concept available. Patch available. Sources: github_commit, github, redhat.
redhat Patch Available
redhat Patch Available
redhat Patch Available
redhat Patch Available
redhat Patch Available
redhat Patch Available
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-g8gggithub_commit Patch Available
commit b87c32ed07b8 (authlib/authlib)
Patch available: authlib/authlib v1.6.7 (contains commit b87c32ed07b8)
https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7github_commit Patch Available
commit a61c2acb8074 (authlib/authlib)
Patch available: authlib/authlib v1.6.0 (contains commit a61c2acb8074)
https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75Vendor 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.
- RHSA-2026:19375Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.16.4
- RHSA-2026:6568Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.15.4
- RHSA-2026:6404Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.6 Container Release Update
- RHSA-2026:6309Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.6 Container Release Update
- RHSA-2026:5665Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.10.19
- RHSA-2026:5168Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.9.19
- RHSA-2026:4942Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.12.15
Patch Availability(6)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| redhat | quay/quay-rhel9:1779204086 | 2026-05-19 | redhat |
| redhat | quay/quay-rhel8:1775169219 | 2026-04-03 | redhat |
| redhat | ansible-automation-platform-26/lightspeed-chatbot-rhel9:1774417022 | 2026-04-01 | redhat |
| redhat | quay/quay-rhel8:1773971077 | 2026-03-24 | redhat |
| redhat | quay/quay-rhel8:1773936323 | 2026-03-19 | redhat |
| redhat | quay/quay-rhel8:1773771962 | 2026-03-18 | redhat |
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
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| authlib | 1.6.5, 1.6.6 | 1.6.7 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 12× 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.
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 04:34 UTCEG score recompute
- 2026-06-30 04:34 UTCVendor advisory
- 2026-06-30 04:31 UTCNVD updatefirst tracked
Related CVEs(same vendor + same CWE)
Same vendor
10 shownredhat
Same CWE
10 shownCWE-347
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 July 1, 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 34.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-28802?
CVE-2026-28802 has a CVSS v3 base score of 9.8 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
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
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-28802
Is Your Infrastructure Affected by CVE-2026-28802?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.