Security incident · AZL-101096
CVE-2026-53939 affecting package cjose 0.6.2.2-7
Published Sep 9, 2026 · catalog updated Oct 22, 2026 · affecting package cjose 0.6.2.2-7
Open the advisory
Exploitation likelihood is not on this record for AZL-101096. A missing EPSS score is not a low risk. Compare affecting package cjose 0.6.2.2-7 with the linked advisory before you change production.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (affecting package cjose 0.6.2.2-7).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- EPSS is missing. A missing score is not a low risk.
- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- Awaiting synchronization with FIRST
- Remediation
- Not established
- Affected products
- Azure Linux:3 cjose
OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). In versions 0.6.1 through 0.6.2.5, when cjose encrypts a JWE using an AES-CBC-HMAC content-encryption algorithm ( , , or ) together with any key-management algorithm that generates a fresh content-encryption key (CEK), the CEK is all zero bytes instead of being randomly generated. The resulting JWE is therefore encrypted and authenticated under a fixed, publicly known key, so anyone who obtains the JWE can recover the plaintext and forge or modify the content. This is fixed in version 0.6.2.6 by generating the CEK from . A regression test asserts that the differs across two encryptions for each AES-CBC-HMAC variant. Until upgrading, for data encrypted with cjose, three options are available. Use an AES-GCM ( / / ) instead of an AES-CBC-HMAC , use with a caller-supplied CEK, or avoid using cjose for JWE encryption with the affected algorithm pair. These are mitigations for new ciphertexts only; data already encrypted under the zero key remains compromised and should be re-encrypted (and any secrets it contained rotated).
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- Azure Linux:3 cjose0 → 0.6.2.2-7
How to fix AZL-101096
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
Exploitation likelihood is not on this record for AZL-101096. A missing EPSS score is not a low risk. Compare affecting package cjose 0.6.2.2-7 with the linked advisory before you change production.
Which versions are affected?
Compare what you have installed with 0 → 0.6.2.2-7. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS is not on this record yet. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Sep 9, 2026 · OpenSSF OSV / OSV Scanner
Detected
OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). In versions 0.6.1 through 0.6.2.5, when cjose encrypts a JWE using an AES-CBC-HMAC content-encryption algorithm ( , , or ) together with any key-management algorithm that generates a fresh content-encryption key (CEK), the CEK is all zero bytes instead of being randomly generated. The resulting JWE is th
Oct 22, 2026 · OpenSSF OSV / OSV Scanner
Fix available
cjose fixed in 0.6.2.2-7
Oct 22, 2026 · OpenSSF OSV / OSV Scanner
Updated
OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). In versions 0.6.1 through 0.6.2.5, when cjose encrypts a JWE using an AES-CBC-HMAC content-encryption algorithm ( , , or ) together with any key-management algorithm that generates a fresh content-encryption key (CEK), the CEK is all zero bytes instead of being randomly generated. The resulting JWE is th
Sources
- OpenSSF OSV / OSV ScannerPackage advisoryAZL-101096
CVE-2026-53939 affecting package cjose 0.6.2.2-7
osv.dev
References
Freshness
Last verified in this catalog Oct 22, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.