{"answers":{"affected":"2 open source packages ship an affected version, including katex.","exploited":"There is no known exploitation of CVE-2026-103923 in the wild and no public exploit code.","fix":"Upgrade katex to 0.18.2 or later.","what":"CVE-2026-103923 is a low-severity cross-site scripting vulnerability in KaTeX, published on 1 Oct 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-2026-103923 and fix it if it is affected.\n\nWhat it is: CVE-2026-103923 is a low-severity cross-site scripting vulnerability in KaTeX, published on 1 Oct 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-2026-103923 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- katex (npm): affected from 0.11.0; fixed in 0.18.2\n- katex (npm): affected from 0.11.0; fixed in 0.18.2\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-2026-103923/ (Markdown: https://insights.sbomify.com/CVE-2026-103923/index.md)","id":"CVE-2026-103923","markdown":"https://insights.sbomify.com/CVE-2026-103923/index.md","name":"CVE-2026-103923","record":{"aliases":["CLSA-2026-1791284260","CLSA-2026-1792488994","DEBIAN-CVE-2026-103923","GHSA-238p-pmpm-9mq7","MINI-p78h-7q25-wggj","MINI-rhmf-wcw9-4rrr","UBUNTU-CVE-2026-103923","openSUSE-SU-2026:12075-1"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"JavaScript math rendering library","requires_auth":"none","summary":"Prototype pollution allows bypassing trust restrictions in KaTeX, enabling XSS via malicious math expressions in applications rendering unsanitized output.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":2.1,"severity":"low","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-807","name":"Reliance on Untrusted Inputs in a Security Decision"}],"description":"KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web. From 0.11.0 until 0.18.2, KaTeX uses ordinary JavaScript property access for the renderer options object, the trust setting, default and processor setting metadata, and namespace lookup and group restoration, allowing inherited properties to be treated as explicitly supplied values. When Object.prototype is already polluted or an attacker controls the options object's prototype, attacker-controlled mathematical expressions can use an inherited trust value to enable trusted rendering and produce links capable of user-interaction cross-site scripting or loading attacker-selected external resources in a consuming application that inserts unsanitized KaTeX output into a page. KaTeX does not itself create the prototype pollution, and rendering an expression alone does not execute script. This issue is fixed in version 0.18.2.","ecosystems":["npm","openSUSE:Tumbleweed"],"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":"KaTeX: Existing prototype pollution can bypass trust restrictions","id":"CVE-2026-103923","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":3,"n_references":4,"next":{"headline":"Metabase: Arbitrary File Read/Write via Unsafe H2 Built-in Functions","id":"CVE-2026-103928"},"packages":[{"ecosystem":"npm","fixed":["0.18.2"],"introduced":["0.11.0"],"last_affected":[],"package":"katex","purl":null,"source":"GHSA-238p-pmpm-9mq7"},{"ecosystem":"npm","fixed":["0.18.2"],"introduced":["0.11.0"],"last_affected":[],"package":"katex","purl":"pkg:npm/katex","source":"GHSA-238p-pmpm-9mq7"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["0.5.3-3.1"],"introduced":["0"],"last_affected":[],"package":"python-jupyterlab-templates","purl":"pkg:rpm/opensuse/python-jupyterlab-templates\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2026:12075-1"}],"prev":{"headline":"Capacitor Android and iOS: remote content can be loaded at the app origin via the internal HTTP proxy path","id":"CVE-2026-103922"},"products":["KaTeX"],"published":"2026-10-01","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":"CC BY 4.0","name":"SUSE","prefix":"openSUSE"},{"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":"2026-10-06","vendors":["KaTeX"]},"summary":"Prototype pollution allows bypassing trust restrictions in KaTeX, enabling XSS via malicious math expressions in applications rendering unsanitized output.","url":"https://insights.sbomify.com/CVE-2026-103923/"}