{"answers":{"affected":"3 open source packages ship an affected version, including cowlib. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-43969 in the wild and no public exploit code.","fix":"Upgrade cowlib to 2.21.0 or later.","what":"CVE-2026-43969 is a low-severity vulnerability in ninenines cowlib, published on 11 May 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-43969 and fix it if it is affected.\n\nWhat it is: CVE-2026-43969 is a low-severity vulnerability in ninenines cowlib, published on 11 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-43969 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- cowlib (Hex): affected from 2.9.0 up to 2.16.1; no fix listed\n- cowlib (Hex): affected from 2.9.0 up to 2.16.1; no fix listed\n- cowlib (Hex): affected from 2.9.0; fixed in 2.21.0\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-2026-43969/ (Markdown: https://insights.sbomify.com/CVE-2026-43969/index.md)","id":"CVE-2026-43969","markdown":"https://insights.sbomify.com/CVE-2026-43969/index.md","name":"CVE-2026-43969","record":{"aliases":["AZL-86787","EEF-CVE-2026-43969","GHSA-g2wm-735q-3f56"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_modify","security_bypass"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Erlang HTTP library","requires_auth":"none","summary":"Attackers can inject CRLF sequences into cookie headers via cowlib, enabling cookie smuggling and HTTP request splitting against upstream proxies.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"EEF","cpe":[{"product":"cowlib","vendor":"ninenines"}],"cvss":{"score":2.1,"severity":"low","source":"cna","vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-93","name":"Improper Neutralization of CRLF Sequences"}],"description":"Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in ninenines cowlib allows HTTP request splitting and cookie smuggling via unvalidated cookie name and value fields.\n\ncow_cookie:cookie/1 in cowlib builds a client-side Cookie: request header from a list of name-value pairs without validating either field. An attacker who controls the cookie names or values passed to this function can inject ;, ,, CR, LF, or TAB characters into the serialized header. This enables two classes of attack: cookie smuggling within a single header (e.g. injecting ; admin=1 to introduce a phantom cookie that the receiving server treats as authentic) and HTTP request header splitting (injecting CRLF to append arbitrary headers or smuggle a complete second request against a shared upstream proxy). The decoder side (parse_cookie_name/1, parse_cookie_value/1) and setcookie/3 already validate and reject these characters; the encoder alone is missing the check.\n\nThis issue affects cowlib: from 2.9.0 before 2.21.0.","ecosystems":["Hex"],"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":"Cookie Request Header Injection via Unvalidated Encoder in cow_cookie:cookie/1","id":"CVE-2026-43969","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Hex","product":null,"products":[],"type":"other","year":"2026"},"n_packages":3,"n_references":5,"next":{"headline":"Decompression Bomb in cow_spdy:inflate/2 Allows Memory Exhaustion via Crafted SPDY Frame","id":"CVE-2026-43970"},"packages":[{"ecosystem":"Hex","fixed":[],"introduced":["2.9.0"],"last_affected":["2.16.1"],"package":"cowlib","purl":null,"source":"GHSA-g2wm-735q-3f56"},{"ecosystem":"Hex","fixed":[],"introduced":["2.9.0"],"last_affected":["2.16.1"],"package":"cowlib","purl":"pkg:hex/cowlib","source":"GHSA-g2wm-735q-3f56"},{"ecosystem":"Hex","fixed":["2.21.0"],"introduced":["2.9.0"],"last_affected":[],"package":"cowlib","purl":"pkg:hex/cowlib","source":"EEF-CVE-2026-43969"}],"prev":{"headline":"CR Injection in SSE Encoder Enables Event Splitting via cow_sse:event/1","id":"CVE-2026-43968"},"products":["cowlib"],"published":"2026-05-11","related":[{"cvss_score":8.7,"headline":"Unbounded chunk-size hex digits in cowlib cause quadratic CPU and memory DoS","id":"CVE-2026-7790","kev_date_added":null,"published":"2026-05-11"},{"cvss_score":6.3,"headline":"HTTP Response Splitting via Non-VCHAR Bytes in cow_http_struct_hd:escape_string/2","id":"CVE-2026-43966","kev_date_added":null,"published":"2026-06-08"},{"cvss_score":6.3,"headline":"CR Injection in SSE Encoder Enables Event Splitting via cow_sse:event/1","id":"CVE-2026-43968","kev_date_added":null,"published":"2026-05-11"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"Erlang Ecosystem Foundation","prefix":"EEF"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-09","vendors":["ninenines"]},"summary":"Attackers can inject CRLF sequences into cookie headers via cowlib, enabling cookie smuggling and HTTP request splitting against upstream proxies.","url":"https://insights.sbomify.com/CVE-2026-43969/"}