{"answers":{"affected":"It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73257 exists.","fix":"Upgrade to a fixed version.","what":"CVE-2026-73257 is a critical vulnerability in Cesanta Mongoose, published on 20 Aug 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-2026-73257 and fix it if it is affected.\n\nWhat it is: CVE-2026-73257 is a critical vulnerability in Cesanta Mongoose, published on 20 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73257 exists.\n\nAffected product: Cesanta Mongoose. No package-level version data is available, so check the vendor advisory linked from the reference page.\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-2026-73257/ (Markdown: https://insights.sbomify.com/CVE-2026-73257/index.md)","id":"CVE-2026-73257","markdown":"https://insights.sbomify.com/CVE-2026-73257/index.md","name":"CVE-2026-73257","record":{"aliases":["DEBIAN-CVE-2026-73257","GHSA-5wfq-r6mr-wqp6","JLSEC-2026-1381","UBUNTU-CVE-2026-73257"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["data_read","data_modify"],"network_reachable":"yes","non_default_config":false,"product_category":"Embedded web server","requires_auth":"none","summary":"Remote attackers can exploit HTTP request smuggling in Mongoose to access or modify resources in other user contexts via CL.TE desynchronization.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mongoose","vendor":"cesanta"}],"cvss":{"score":9.1,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-444","name":"Inconsistent Interpretation of HTTP Requests"}],"description":"Mongoose is an embedded web server and network library. Priro to version 7.22, a remote unauthenticated attacker can send an HTTP request containing both Content-Length and Transfer-Encoding: chunked. The cl_count and te_count checks in the mg_http_parse() and http_cb() paths in src/http.c accept both headers and prioritize chunked encoding, while a Content-Length-preferring reverse proxy can use a different request boundary. This CL.TE desynchronization can inject requests that access or modify resources in another user context. This issue is fixed in version 7.22.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"Mongoose: Content-Length + Transfer-Encoding coexistence enables request smuggling","id":"CVE-2026-73257","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"cesanta:mongoose","products":["cesanta:mongoose"],"type":"other","year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"Mongoose: Multipart boundary/header scan logic error in mg_http_next_multipart","id":"CVE-2026-73258"},"packages":[],"prev":{"headline":"Mongoose: HTTP/1.0 detection off-by-one enables request smuggling via chunked TE","id":"CVE-2026-73256"},"products":["mongoose"],"published":"2026-08-20","related":[{"cvss_score":9.8,"headline":"Arbitrary File Write","id":"CVE-2022-25299","kev_date_added":null,"published":"2022-02-18"},{"cvss_score":9.8,"headline":"Memory corruption in n/a","id":"CVE-2020-25756","kev_date_added":null,"published":"2020-09-18"},{"cvss_score":9.8,"headline":"Integer overflow in n/a","id":"CVE-2019-19307","kev_date_added":null,"published":"2019-11-26"},{"cvss_score":9.8,"headline":"Memory corruption in n/a","id":"CVE-2019-12951","kev_date_added":null,"published":"2019-06-24"},{"cvss_score":9.8,"headline":"Use after free in n/a","id":"CVE-2018-20353","kev_date_added":null,"published":"2019-06-10"},{"cvss_score":9.8,"headline":"Use after free in n/a","id":"CVE-2018-20354","kev_date_added":null,"published":"2019-06-10"},{"cvss_score":9.8,"headline":"Use after free in n/a","id":"CVE-2018-20355","kev_date_added":null,"published":"2019-06-10"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-08-20","vendors":["cesanta"]},"summary":"Remote attackers can exploit HTTP request smuggling in Mongoose to access or modify resources in other user contexts via CL.TE desynchronization.","url":"https://insights.sbomify.com/CVE-2026-73257/"}