{"answers":{"affected":"4 open source packages ship an affected version, including mermaid.","exploited":"There is no known exploitation of CVE-2026-41148 in the wild and no public exploit code.","fix":"Upgrade mermaid to a fixed version for your release line: 10.9.6 or 11.15.0.","what":"CVE-2026-41148 is a medium-severity cross-site scripting vulnerability in mermaid-js mermaid, published on 22 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-41148 and fix it if it is affected.\n\nWhat it is: CVE-2026-41148 is a medium-severity cross-site scripting vulnerability in mermaid-js mermaid, published on 22 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-41148 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- mermaid (npm): affected all versions; fixed in 10.9.6\n- mermaid (npm): affected all versions; fixed in 10.9.6\n- mermaid (npm): affected from 11.0.0-alpha.1; fixed in 11.15.0\n- mermaid (npm): affected from 11.0.0-alpha.1; fixed in 11.15.0\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-2026-41148/ (Markdown: https://insights.sbomify.com/CVE-2026-41148/index.md)","id":"CVE-2026-41148","markdown":"https://insights.sbomify.com/CVE-2026-41148/index.md","name":"CVE-2026-41148","record":{"aliases":["DEBIAN-CVE-2026-41148","GHSA-xcj9-5m2h-648r","MINI-hg26-fchg-r9q7","MINI-mr8r-fjhr-xmxx","UBUNTU-CVE-2026-41148"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"JavaScript diagramming library","requires_auth":"none","summary":"Attackers can inject malicious CSS via classDef values in Mermaid diagrams, enabling page defacement, user tracking, and DOM attribute exfiltration.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L","version":"4.0"},"cwes":[{"id":"CWE-94","name":"Improper Control of Generation of Code"}],"description":"Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Versions 10.9.5 and prior, in addition to 11.0.0-alpha.1 through 11.12.0 are vulnerable to CSS injection through improper sanitization. The state diagram (and any other diagram type that routes user-controlled style strings through the createCssStyles parser) captures classDef values using an unrestricted regex that matches everything up to a newline. That value then flows unsanitized through addStyleClass() into createCssStyles() and is assigned to style.innerHTML, so a closing brace (}) in the value terminates the generated CSS selector and turns everything after it into a new CSS rule on the page. This enables page defacement, user tracking via url() callbacks, and DOM attribute exfiltration. This issue has been fixed in versions 10.9.6 and 11.15.0. If developers are unable to immediately upgrade, they can work around this issue by setting \"securityLevel\": \"sandbox\", which prevents the issue by rendering the mermaid diagram in a sandboxed \u003ciframe\u003e.","ecosystems":["npm"],"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":"Mermaid: Improper sanitization of `classDefs` in diagrams leads to CSS injection","id":"CVE-2026-41148","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":4,"n_references":6,"next":{"headline":"Mermaid: Improper sanitization of `classDef` in state diagrams leads to HTML injection","id":"CVE-2026-41149"},"packages":[{"ecosystem":"npm","fixed":["10.9.6"],"introduced":["0"],"last_affected":[],"package":"mermaid","purl":null,"source":"GHSA-xcj9-5m2h-648r"},{"ecosystem":"npm","fixed":["10.9.6"],"introduced":["0"],"last_affected":[],"package":"mermaid","purl":"pkg:npm/mermaid","source":"GHSA-xcj9-5m2h-648r"},{"ecosystem":"npm","fixed":["11.15.0"],"introduced":["11.0.0-alpha.1"],"last_affected":[],"package":"mermaid","purl":null,"source":"GHSA-xcj9-5m2h-648r"},{"ecosystem":"npm","fixed":["11.15.0"],"introduced":["11.0.0-alpha.1"],"last_affected":[],"package":"mermaid","purl":"pkg:npm/mermaid","source":"GHSA-xcj9-5m2h-648r"}],"prev":{"headline":"NukeViet CMS: Stored Cross-Site Scripting (XSS) via insufficient server-side input sanitization in Request class","id":"CVE-2026-41147"},"products":["mermaid"],"published":"2026-05-22","related":[],"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":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-27","vendors":["mermaid-js"]},"summary":"Attackers can inject malicious CSS via classDef values in Mermaid diagrams, enabling page defacement, user tracking, and DOM attribute exfiltration.","url":"https://insights.sbomify.com/CVE-2026-41148/"}