---
cve: "CVE-2026-53938"
severity: "HIGH"
cvss: 8.2
epss: "0.2%"
vendor: "OpenIDC"
kev: false
exploited: false
published: "2026-09-09 00:17:31"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T16:10:09+02:00"
---

# CVE-2026-53938

> 8.2 HIGH · 🧪 PoC

## Beschreibung

OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). Prior to version 0.6.2.5, cjose's JWE decryption path for the AES Key Wrap key-management algorithms (`alg` = `A128KW`, `A192KW`, `A256KW`) does not validate the length of the attacker-supplied `encrypted_key` (JWE Encrypted Key) before unwrapping it into a fixed-size, heap-allocated Content Encryption Key (CEK) buffer. A remote, unauthenticated attacker who can submit a crafted JWE to an application that decrypts it with an AES-KW symmetric key can trigger an out-of-bounds heap write, corrupting the heap. This leads at minimum to a crash (denial of service) and, depending on the heap layout and allocator, may be leverageable for further memory-corruption impact. `cjose_jwe_import()` / `cjose_jwe_decrypt()` are pre-authentication entry points: they parse and process fully attacker-controlled input. Upgrade to cjose 0.6.2.5 to receive a patch. If upgrading is not immediately possible, reject the AES Key Wrap algorithms (`A128KW`/`A192KW`/`A256KW`) for untrusted JWEs at the application layer.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Gering | warn |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- 8c51d245273583a658f24ef7b08ba22f848a34a5 (Commit)

## Referenzen

- <https://github.com/OpenIDC/cjose/security/advisories/GHSA-75r7-f5cv-g3wj>
- <https://github.com/OpenIDC/cjose/commit/8c51d245273583a658f24ef7b08ba22f848a34a5>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53938) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_