{"answers":{"affected":"4 open source packages ship an affected version, including livewire/livewire.","exploited":"There is no known exploitation of CVE-2026-81887 in the wild and no public exploit code.","fix":"Upgrade livewire/livewire to a fixed version for your release line: 3.8.3 or 4.3.4.","what":"CVE-2026-81887 is a medium-severity cross-site scripting vulnerability in livewire, published on 31 Aug 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-2026-81887 and fix it if it is affected.\n\nWhat it is: CVE-2026-81887 is a medium-severity cross-site scripting vulnerability in livewire, published on 31 Aug 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-2026-81887 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- livewire/livewire (Packagist): affected from 3.0.0-beta.1; fixed in 3.8.3\n- livewire/livewire (Packagist): affected from 3.0.0-beta.1; fixed in 3.8.3\n- livewire/livewire (Packagist): affected from 4.0.0-beta.1; fixed in 4.3.4\n- livewire/livewire (Packagist): affected from 4.0.0-beta.1; fixed in 4.3.4\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-2026-81887/ (Markdown: https://insights.sbomify.com/CVE-2026-81887/index.md)","id":"CVE-2026-81887","markdown":"https://insights.sbomify.com/CVE-2026-81887/index.md","name":"CVE-2026-81887","record":{"aliases":["CLSA-2026-1790868445","CLSA-2026-1790868699","GHSA-g3hc-697w-wm82"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Livewire Laravel framework","requires_auth":"none","summary":"An attacker can execute arbitrary JavaScript in the user's browser via a crafted URL due to prototype pollution in Livewire's client-side state handling.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":5.1,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"},{"id":"CWE-1321","name":"Improperly Controlled Modification of Object Prototype Attributes"}],"description":"Livewire is a full-stack framework for Laravel. From 3.0.0-beta.1 until 3.8.3 and 4.3.4, the dot-notated query-string parser in js/plugins/history/index.js, including fromQueryString() and insertDotNotatedValueIntoData(), accepts the __proto__, constructor, and prototype path segments and creates inherited objects. Client-side state handlers then access effects.html, effects.js, effects.xjs, and effects.scripts without Object.prototype.hasOwnProperty.call(), allowing inherited attacker-controlled state to be treated as trusted effects. An unauthenticated attacker can craft a URL that, when opened by a user, executes arbitrary JavaScript in the affected application's origin. Exploitation requires user interaction and does not bypass server-side authorization or grant privileges beyond the affected user. This issue is fixed in versions 3.8.3 and 4.3.4.","ecosystems":["Packagist"],"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":"Livewire DOM-based cross-site scripting during client-side state handling","id":"CVE-2026-81887","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Packagist","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":4,"n_references":5,"next":{"headline":"@hono/oauth-providers: OAuth state check fails open on omitted state, enabling login CSRF and forced account linking","id":"CVE-2026-81888"},"packages":[{"ecosystem":"Packagist","fixed":["3.8.3"],"introduced":["3.0.0-beta.1"],"last_affected":[],"package":"livewire/livewire","purl":null,"source":"GHSA-g3hc-697w-wm82"},{"ecosystem":"Packagist","fixed":["3.8.3"],"introduced":["3.0.0-beta.1"],"last_affected":[],"package":"livewire/livewire","purl":"pkg:composer/livewire/livewire","source":"GHSA-g3hc-697w-wm82"},{"ecosystem":"Packagist","fixed":["4.3.4"],"introduced":["4.0.0-beta.1"],"last_affected":[],"package":"livewire/livewire","purl":null,"source":"GHSA-g3hc-697w-wm82"},{"ecosystem":"Packagist","fixed":["4.3.4"],"introduced":["4.0.0-beta.1"],"last_affected":[],"package":"livewire/livewire","purl":"pkg:composer/livewire/livewire","source":"GHSA-g3hc-697w-wm82"}],"prev":{"headline":"radare2: Uncontrolled memory allocation in radare2 dmp64 parser","id":"CVE-2026-81886"},"products":["livewire"],"published":"2026-08-31","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":"2026-09-03","vendors":["livewire"]},"summary":"An attacker can execute arbitrary JavaScript in the user's browser via a crafted URL due to prototype pollution in Livewire's client-side state handling.","url":"https://insights.sbomify.com/CVE-2026-81887/"}