{"answers":{"affected":"2 open source packages ship an affected version, including @astrojs/rss.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-59728 exists.","fix":"Upgrade @astrojs/rss to 4.0.19 or later.","what":"CVE-2026-59728 is a medium-severity vulnerability in withastro astro, published on 27 Jul 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-2026-59728 and fix it if it is affected.\n\nWhat it is: CVE-2026-59728 is a medium-severity vulnerability in withastro astro, published on 27 Jul 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-59728 exists.\n\nAffected packages and fixed versions:\n- @astrojs/rss (npm): affected from 1.0.0; fixed in 4.0.19\n- @astrojs/rss (npm): affected from 1.0.0; fixed in 4.0.19\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-2026-59728/ (Markdown: https://insights.sbomify.com/CVE-2026-59728/index.md)","id":"CVE-2026-59728","markdown":"https://insights.sbomify.com/CVE-2026-59728/index.md","name":"CVE-2026-59728","record":{"aliases":["CLSA-2026-1784596299","CLSA-2026-1784943236","CLSA-2026-1792161555","CLSA-2026-1792161559","CLSA-2026-1792161694","CLSA-2026-1792161701","CLSA-2026-1792161786","CLSA-2026-1792161789","CLSA-2026-1792161855","CLSA-2026-1793093746","CLSA-2026-1793093842","GHSA-8j5q-mfj2-5q9q"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_modify","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Astro RSS library","requires_auth":"none","summary":"Attackers can inject malicious XML into RSS feeds via unescaped fields, corrupting feed structure and injecting false metadata for subscribers.","user_interaction":"required","vuln_class":"xxe"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":4.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-91","name":"XML Injection"}],"description":"Astro is a web framework for content-driven websites. In versions 1.0.0 through 4.0.18, the source.title and enclosure.type item fields in packages/astro-rss/src/index.ts are interpolated directly into XML template strings without XML-character escaping before being parsed by fast-xml-parser. Both fields are validated only as z.string(), placing no restriction on XML special characters. An attacker who controls these values can inject arbitrary XML into the generated RSS feed: a value containing \" can break out of an attribute (as with enclosure.type), and a value containing \u003c/source\u003e can close an element early and inject additional nodes (as with source.title). This corrupts feed structure, injects false metadata (for example, a fake \u003clink\u003e pointing to a malicious URL), and can cause feed readers to misparse or display attacker-controlled content. In SSR mode (output: 'server'), the poisoned feed is served on every request to all subscribers. This issue has been fixed in version 4.0.19.","ecosystems":["npm"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"@astrojs/rss: XML Injection via Unescaped RSS Feed Fields","id":"CVE-2026-59728","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":"xxe","year":"2026"},"n_packages":2,"n_references":4,"next":{"headline":"Astro: XSS via unescaped spread attribute names in renderHTMLElement (incomplete fix for CVE-2026-54298)","id":"CVE-2026-59729"},"packages":[{"ecosystem":"npm","fixed":["4.0.19"],"introduced":["1.0.0"],"last_affected":[],"package":"@astrojs/rss","purl":null,"source":"GHSA-8j5q-mfj2-5q9q"},{"ecosystem":"npm","fixed":["4.0.19"],"introduced":["1.0.0"],"last_affected":[],"package":"@astrojs/rss","purl":"pkg:npm/%40astrojs/rss","source":"GHSA-8j5q-mfj2-5q9q"}],"prev":{"headline":"Astro: Cross-site scripting via unescaped transition:* directive values on hydrated islands","id":"CVE-2026-59727"},"products":["astro"],"published":"2026-07-27","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":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-28","vendors":["withastro"]},"summary":"Attackers can inject malicious XML into RSS feeds via unescaped fields, corrupting feed structure and injecting false metadata for subscribers.","url":"https://insights.sbomify.com/CVE-2026-59728/"}