{"answers":{"affected":"1 open source package ship an affected version, including nimble_zta.","exploited":"There is no known exploitation of CVE-2026-91187 in the wild and no public exploit code.","fix":"Upgrade nimble_zta to 0.1.3 or later.","what":"CVE-2026-91187 is a critical authentication bypass vulnerability in dashbit nimble_zta, published on 24 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-2026-91187 and fix it if it is affected.\n\nWhat it is: CVE-2026-91187 is a critical authentication bypass vulnerability in dashbit nimble_zta, published on 24 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-91187 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- nimble_zta (Hex): affected from 0.1.2; fixed in 0.1.3\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-2026-91187/ (Markdown: https://insights.sbomify.com/CVE-2026-91187/index.md)","id":"CVE-2026-91187","markdown":"https://insights.sbomify.com/CVE-2026-91187/index.md","name":"CVE-2026-91187","record":{"aliases":["EEF-CVE-2026-91187","GHSA-rj24-g8cc-g7g2"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["account_takeover","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Elixir Zero Trust library","requires_auth":"none","summary":"An unauthenticated attacker can bypass Cloudflare Zero Trust authentication by sending a forged JWT, allowing them to impersonate any service token.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"EEF","cpe":[],"cvss":{"score":9.3,"severity":"critical","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:N","version":"4.0"},"cwes":[{"id":"CWE-347","name":"Improper Verification of Cryptographic Signature"}],"description":"Improper Verification of Cryptographic Signature vulnerability in dashbit nimble_zta allows an unauthenticated remote attacker to authenticate as an arbitrary Cloudflare service token. Applications using the Cloudflare Zero Trust authentication strategy are affected.\n\nverify_token/2 in lib/nimble_zta/cloudflare.ex matches the result of JOSE.JWT.verify/2 against {_, token, _s}, which discards the boolean verification result and returns the decoded token after a failed signature check. The attacker sends a forged JWT in the cf-access-jwt-assertion header, carrying the expected iss claim and the seven service token claims. verify_iss/2 reads the iss claim from the forged token, so it rejects nothing, and the service token path then returns those claims as the authenticated identity.\n\nThis issue affects nimble_zta: from 0.1.2 before 0.1.3.","ecosystems":["Hex"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Improper Verification of Cryptographic Signature in dashbit nimble_zta Cloudflare strategy","id":"CVE-2026-91187","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Hex","product":null,"products":[],"type":"auth_bypass","year":"2026"},"n_packages":1,"n_references":5,"next":{"headline":"The GUIX binary resource loader never checks that a font page's glyph range is well formed.","id":"CVE-2026-91189"},"packages":[{"ecosystem":"Hex","fixed":["0.1.3"],"introduced":["0.1.2"],"last_affected":[],"package":"nimble_zta","purl":"pkg:hex/nimble_zta","source":"EEF-CVE-2026-91187"}],"prev":{"headline":"PNG decoder: a duplicate IHDR chunk after IDAT resizes the image after allocation, causing a heap out-of-bounds write","id":"CVE-2026-91186"},"products":["nimble_zta"],"published":"2026-09-24","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"Erlang Ecosystem Foundation","prefix":"EEF"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-24","vendors":["dashbit"]},"summary":"An unauthenticated attacker can bypass Cloudflare Zero Trust authentication by sending a forged JWT, allowing them to impersonate any service token.","url":"https://insights.sbomify.com/CVE-2026-91187/"}