Heap-based buffer overflow in cjose - CVE-2026-53938

Vulnerability identifier: #VU133239

CSH Severity: High

CVSS v4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53938

CWE-ID: CWE-122

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a heap-based buffer overflow in _cjose_jwe_decrypt_ek_aes_kw() in src/jwe.c when decrypting a crafted JWE using the AES Key Wrap algorithms. A remote attacker can submit a specially crafted JWE with an oversized encrypted_key value to cause a denial of service.

Only deployments that decrypt JWEs with A128KW, A192KW, or A256KW are affected.

cjose
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 12 SP5
Debian Linux
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Real Time 15
Server Applications Module
openSUSE Leap
openEuler
libcjose0
libcjose0-debuginfo
cjose-debugsource
libcjose-devel
cjose (Debian package)
cjose
cjose-debuginfo
cjose-devel

Install security update from vendor's website.

cjose - update to 0.6.2.5
libcjose0 - addressed in versions 0.6.1-7.8.1, 0.6.1-150100.4.9.1, 0.6.1-150600.18.3.1
libcjose0-debuginfo - addressed in versions 0.6.1-7.8.1, 0.6.1-150100.4.9.1, 0.6.1-150600.18.3.1
cjose-debugsource - addressed in versions 0.6.1-7.8.1, 0.6.1-150100.4.9.1, 0.6.1-150600.18.3.1
libcjose-devel - addressed in versions 0.6.1-150100.4.9.1, 0.6.1-150600.18.3.1
cjose (Debian package) - update to 0.6.2.3-1+deb13u1
cjose - update to 0.6.2.7-1
cjose-debuginfo - update to 0.6.2.7-1
cjose-debugsource - update to 0.6.2.7-1
cjose-devel - update to 0.6.2.7-1

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

• Heap-based buffer overflow in cjose
• Debian update for cjose
• SUSE update for cjose
• SUSE update for cjose
• SUSE update for cjose
• openEuler update for cjose