{"answers":{"affected":"","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53939 exists.","fix":"Upgrade to a fixed version.","what":"CVE-2026-53939 is a critical vulnerability in OpenIDC cjose, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-53939 and fix it if it is affected.\n\nWhat it is: CVE-2026-53939 is a critical vulnerability in OpenIDC cjose, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53939 exists.\n\nAffected product: OpenIDC cjose. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-53939/ (Markdown: https://insights.sbomify.com/CVE-2026-53939/index.md)","id":"CVE-2026-53939","markdown":"https://insights.sbomify.com/CVE-2026-53939/index.md","name":"CVE-2026-53939","record":{"aliases":["ALSA-2026:80605","ALSA-2026:92145","ALSA-2026:92157","AZL-101096","CLSA-2026-1792632603","DEBIAN-CVE-2026-53939","GHSA-f6wf-pqg3-6wqq","RHSA-2026:80605","RHSA-2026:83224","RLSA-2026:80605","RLSA-2026:92157","UBUNTU-CVE-2026-53939"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","data_modify"],"network_reachable":"yes","non_default_config":false,"product_category":"JOSE C library","requires_auth":"none","summary":"Attackers can decrypt and forge JWE tokens because the library uses an all-zero key for AES-CBC-HMAC encryption, compromising confidentiality and integrity.","user_interaction":"not_required","vuln_class":"weak_cryptography"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":9.1,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-330","name":"Use of Insufficiently Random Values"},{"id":"CWE-321","name":"Use of Hard-coded Cryptographic Key"}],"description":"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 (`A128CBC-HS256`, `A192CBC-HS384`, or `A256CBC-HS512`) 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 `_cjose_jwe_set_cek_aes_cbc()` generating the CEK from `RAND_bytes`. A regression test asserts that the `encrypted_key` 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 `enc` (`A128GCM` / `A192GCM` / `A256GCM`) instead of an AES-CBC-HMAC `enc`,  use `alg=dir` 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).","ecosystems":["AlmaLinux:10","AlmaLinux:8","AlmaLinux:9","Red Hat:enterprise_linux:10.2","Red Hat:enterprise_linux_eus:10.0","Rocky Linux:10","Rocky Linux:8"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"OpenIDC/cjose uses all-zero Content Encryption Key for AES-CBC-HMAC JWE encryption","id":"CVE-2026-53939","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"weak_cryptography","year":"2026"},"n_packages":17,"n_references":3,"next":{"headline":"Conda: Entry-point path traversal in noarch:python install (arbitrary file write) — canonical Python implementation","id":"CVE-2026-53940"},"packages":[{"ecosystem":"AlmaLinux:10","fixed":["0.6.2.2-7.el10_2.2"],"introduced":["0"],"last_affected":[],"package":"cjose","purl":"pkg:rpm/almalinux/cjose","source":"ALSA-2026:80605"},{"ecosystem":"AlmaLinux:10","fixed":["0.6.2.2-7.el10_2.2"],"introduced":["0"],"last_affected":[],"package":"cjose-devel","purl":"pkg:rpm/almalinux/cjose-devel","source":"ALSA-2026:80605"},{"ecosystem":"AlmaLinux:8","fixed":["0.6.1-6.module_el8.10.0+4330+15616d81"],"introduced":["0"],"last_affected":[],"package":"cjose","purl":"pkg:rpm/almalinux/cjose","source":"ALSA-2026:92157"},{"ecosystem":"AlmaLinux:8","fixed":["0.6.1-6.module_el8.10.0+4330+15616d81"],"introduced":["0"],"last_affected":[],"package":"cjose-devel","purl":"pkg:rpm/almalinux/cjose-devel","source":"ALSA-2026:92157"},{"ecosystem":"AlmaLinux:8","fixed":["2.4.9.4-9.module_el8.10.0+4297+63ae3533"],"introduced":["0"],"last_affected":[],"package":"mod_auth_openidc","purl":"pkg:rpm/almalinux/mod_auth_openidc","source":"ALSA-2026:92157"},{"ecosystem":"AlmaLinux:9","fixed":["0.6.1-17.el9_8.2"],"introduced":["0"],"last_affected":[],"package":"cjose","purl":"pkg:rpm/almalinux/cjose","source":"ALSA-2026:92145"},{"ecosystem":"AlmaLinux:9","fixed":["0.6.1-17.el9_8.2"],"introduced":["0"],"last_affected":[],"package":"cjose-devel","purl":"pkg:rpm/almalinux/cjose-devel","source":"ALSA-2026:92145"},{"ecosystem":"Red Hat:enterprise_linux:10.2","fixed":["0:0.6.2.2-7.el10_2.2"],"introduced":["0"],"last_affected":[],"package":"cjose","purl":"pkg:rpm/redhat/cjose","source":"RHSA-2026:80605"},{"ecosystem":"Red Hat:enterprise_linux:10.2","fixed":["0:0.6.2.2-7.el10_2.2"],"introduced":["0"],"last_affected":[],"package":"cjose-debuginfo","purl":"pkg:rpm/redhat/cjose-debuginfo","source":"RHSA-2026:80605"},{"ecosystem":"Red Hat:enterprise_linux:10.2","fixed":["0:0.6.2.2-7.el10_2.2"],"introduced":["0"],"last_affected":[],"package":"cjose-debugsource","purl":"pkg:rpm/redhat/cjose-debugsource","source":"RHSA-2026:80605"},{"ecosystem":"Red Hat:enterprise_linux:10.2","fixed":["0:0.6.2.2-7.el10_2.2"],"introduced":["0"],"last_affected":[],"package":"cjose-devel","purl":"pkg:rpm/redhat/cjose-devel","source":"RHSA-2026:80605"},{"ecosystem":"Red Hat:enterprise_linux_eus:10.0","fixed":["0:0.6.2.2-7.el10_0.2"],"introduced":["0"],"last_affected":[],"package":"cjose","purl":"pkg:rpm/redhat/cjose","source":"RHSA-2026:83224"},{"ecosystem":"Red Hat:enterprise_linux_eus:10.0","fixed":["0:0.6.2.2-7.el10_0.2"],"introduced":["0"],"last_affected":[],"package":"cjose-debuginfo","purl":"pkg:rpm/redhat/cjose-debuginfo","source":"RHSA-2026:83224"},{"ecosystem":"Red Hat:enterprise_linux_eus:10.0","fixed":["0:0.6.2.2-7.el10_0.2"],"introduced":["0"],"last_affected":[],"package":"cjose-debugsource","purl":"pkg:rpm/redhat/cjose-debugsource","source":"RHSA-2026:83224"},{"ecosystem":"Red Hat:enterprise_linux_eus:10.0","fixed":["0:0.6.2.2-7.el10_0.2"],"introduced":["0"],"last_affected":[],"package":"cjose-devel","purl":"pkg:rpm/redhat/cjose-devel","source":"RHSA-2026:83224"},{"ecosystem":"Rocky Linux:10","fixed":["0:0.6.2.2-7.el10_2.2"],"introduced":["0"],"last_affected":[],"package":"cjose","purl":"pkg:rpm/rocky-linux/cjose?distro=rocky-linux-10\u0026epoch=0","source":"RLSA-2026:80605"},{"ecosystem":"Rocky Linux:8","fixed":["0:2.4.9.4-9.module+el8.10.0+40373+8a3f15d2"],"introduced":["0"],"last_affected":[],"package":"mod_auth_openidc","purl":"pkg:rpm/rocky-linux/mod_auth_openidc?distro=rocky-linux-8\u0026epoch=0","source":"RLSA-2026:92157"}],"prev":{"headline":"OpenIDC/cjose has a heap buffer overflow in AES Key Wrap decryption (A128KW/A192KW/A256KW)","id":"CVE-2026-53938"},"products":["cjose"],"published":"2026-09-08","related":[],"sources":[{"class":"attribution","licence":"MIT","name":"AlmaLinux","prefix":"ALSA"},{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"Red Hat","prefix":"RHSA"},{"class":"attribution","licence":"BSD","name":"Rocky Linux","prefix":"RLSA"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-09-09","vendors":["OpenIDC"]},"summary":"Attackers can decrypt and forge JWE tokens because the library uses an all-zero key for AES-CBC-HMAC encryption, compromising confidentiality and integrity.","url":"https://insights.sbomify.com/CVE-2026-53939/"}