# CVE-2026-53938

## Summary

- **CVE ID:** CVE-2026-53938
- **Severity:** HIGH
- **CVSS Score:** 8.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H)
- **CWE:** CWE-122, CWE-787
- **Published:** Sep 8, 2026
- **Last Modified:** Sep 9, 2026

## Description

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.

## Affected Products

- OpenIDC — cjose (< 0.6.2.5)

## References

- [CNA](https://github.com/OpenIDC/cjose/security/advisories/GHSA-75r7-f5cv-g3wj)
- [CNA](https://github.com/OpenIDC/cjose/commit/8c51d245273583a658f24ef7b08ba22f848a34a5)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.24%
- **EPSS Percentile:** 14.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._