{"answers":{"affected":"3 open source packages ship an affected version, including authlib. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28498 exists.","fix":"Upgrade authlib to 1.6.9 or later.","what":"CVE-2026-28498 is a high-severity vulnerability in authlib, published on 16 Mar 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-2026-28498 and fix it if it is affected.\n\nWhat it is: CVE-2026-28498 is a high-severity vulnerability in authlib, published on 16 Mar 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-2026-28498 exists.\n\nAffected packages and fixed versions:\n- authlib (PyPI): affected all versions; fixed in 1.6.9\n- authlib (PyPI): affected all versions; fixed in 1.6.9\n- authlib (PyPI): affected all versions; fixed in 1.6.9\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-2026-28498/ (Markdown: https://insights.sbomify.com/CVE-2026-28498/index.md)","id":"CVE-2026-28498","markdown":"https://insights.sbomify.com/CVE-2026-28498/index.md","name":"CVE-2026-28498","record":{"aliases":["DEBIAN-CVE-2026-28498","ECHO-435f-9eb9-99cb","GHSA-m344-f55w-2m6j","MINI-84m5-6586-wq2f","MINI-hr69-68cq-v4wq","PYSEC-2026-2117","ROOT-APP-PYPI-CVE-2026-28498","UBUNTU-CVE-2026-28498"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Python OIDC library","requires_auth":"none","summary":"Attackers can bypass OIDC token integrity checks by using unsupported algorithms, allowing forged tokens to be accepted as valid.","user_interaction":"not_required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"authlib","vendor":"authlib"}],"cvss":{"score":8.2,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-325","name":"Missing Cryptographic Step"},{"id":"CWE-573","name":"Improper Following of Specification by Caller"},{"id":"CWE-354","name":"Improper Validation of Integrity Check Value"}],"description":"Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a library-level vulnerability was identified in the Authlib Python library concerning the validation of OpenID Connect (OIDC) ID Tokens. Specifically, the internal hash verification logic (_verify_hash) responsible for validating the at_hash (Access Token Hash) and c_hash (Authorization Code Hash) claims exhibits a fail-open behavior when encountering an unsupported or unknown cryptographic algorithm. This flaw allows an attacker to bypass mandatory integrity protections by supplying a forged ID Token with a deliberately unrecognized alg header parameter. The library intercepts the unsupported state and silently returns True (validation passed), inherently violating fundamental cryptographic design principles and direct OIDC specifications. This issue has been patched in version 1.6.9.","ecosystems":["PyPI"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"Authlib: Fail-Open Cryptographic Verification in OIDC Hash Binding","id":"CVE-2026-28498","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"security_feature_bypass","year":"2026"},"n_packages":3,"n_references":3,"next":{"headline":"LeafKit's HTML escaping may be skipped for Collection values, enabling XSS","id":"CVE-2026-28499"},"packages":[{"ecosystem":"PyPI","fixed":["1.6.9"],"introduced":["0"],"last_affected":[],"package":"authlib","purl":null,"source":"GHSA-m344-f55w-2m6j"},{"ecosystem":"PyPI","fixed":["1.6.9"],"introduced":["0"],"last_affected":[],"package":"authlib","purl":"pkg:pypi/authlib","source":"GHSA-m344-f55w-2m6j"},{"ecosystem":"PyPI","fixed":["1.6.9"],"introduced":["0"],"last_affected":[],"package":"authlib","purl":"pkg:pypi/authlib","source":"PYSEC-2026-2117"}],"prev":{"headline":"TinyWeb: Integer Overflow in `_Val` (HTTP Request Smuggling)","id":"CVE-2026-28497"},"products":["authlib"],"published":"2026-03-16","related":[{"cvss_score":9.1,"headline":"Authlib JWS JWK Header Injection: Signature Verification Bypass","id":"CVE-2026-27962","kev_date_added":null,"published":"2026-03-16"},{"cvss_score":8.3,"headline":"Authlib Vulnerable to JWE RSA1_5 Bleichenbacher Padding Oracle","id":"CVE-2026-28490","kev_date_added":null,"published":"2026-03-16"},{"cvss_score":7.7,"headline":"Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification","id":"CVE-2026-28802","kev_date_added":null,"published":"2026-03-06"},{"cvss_score":7.5,"headline":"Authlib is vulnerable to Denial of Service via Oversized JOSE Segments","id":"CVE-2025-61920","kev_date_added":null,"published":"2025-10-10"},{"cvss_score":7.5,"headline":"Authlib: JWS/JWT accepts unknown crit headers (RFC violation → possible authz bypass)","id":"CVE-2025-59420","kev_date_added":null,"published":"2025-09-22"},{"cvss_score":7.5,"headline":"Authlib has algorithm confusion with asymmetric public keys","id":"CVE-2024-37568","kev_date_added":null,"published":"2024-06-09"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"PyPA Advisory Database","prefix":"PYSEC"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-10","vendors":["authlib"]},"summary":"Attackers can bypass OIDC token integrity checks by using unsupported algorithms, allowing forged tokens to be accepted as valid.","url":"https://insights.sbomify.com/CVE-2026-28498/"}