---
cve: "CVE-2026-28802"
severity: "HIGH"
cvss: 7.7
epss: "0.4%"
vendor: "authlib"
kev: false
exploited: false
published: "2026-03-06 07:16:01"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T07:20:54+02:00"
---

# CVE-2026-28802

> 7.7 HIGH · 🧪 PoC

## Beschreibung

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-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 38e872a3f5b97d2658507acc8762a4e18adaa50e (Commit)
- a61c2acb807496e67f32051b5f1b1d5ccf8f0a75 (Commit)

## Referenzen

- <https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg>
- <https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75>
- <https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7>
- <https://access.redhat.com/errata/RHSA-2026:19375>
- <https://access.redhat.com/errata/RHSA-2026:4942>
- <https://access.redhat.com/errata/RHSA-2026:5168>
- <https://access.redhat.com/errata/RHSA-2026:5665>
- <https://access.redhat.com/errata/RHSA-2026:6309>
- <https://access.redhat.com/errata/RHSA-2026:6568>
- <https://access.redhat.com/security/cve/CVE-2026-28802>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2445120>
- <https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28802.json>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-28802) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_