{"answers":{"affected":"3 open source packages ship an affected version, including gun. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-43972 in the wild and no public exploit code.","fix":"Upgrade gun to 2.4.0 or later.","what":"CVE-2026-43972 is a medium-severity vulnerability in ninenines gun, published on 8 Jun 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-2026-43972 and fix it if it is affected.\n\nWhat it is: CVE-2026-43972 is a medium-severity vulnerability in ninenines gun, published on 8 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-43972 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- gun (Hex): affected from 2.0.0; fixed in 2.4.0\n- gun (Hex): affected from 2.0.0; fixed in 2.4.0\n- gun (Hex): affected from 2.0.0; fixed in 2.4.0\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-2026-43972/ (Markdown: https://insights.sbomify.com/CVE-2026-43972/index.md)","id":"CVE-2026-43972","markdown":"https://insights.sbomify.com/CVE-2026-43972/index.md","name":"CVE-2026-43972","record":{"aliases":["EEF-CVE-2026-43972","GHSA-36w4-95hv-5vwg"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["account_takeover","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Erlang HTTP client","requires_auth":"none","summary":"A malicious HTTP/2 server can inject cookies for arbitrary domains via unvalidated PUSH_PROMISE frames, potentially leading to account takeover.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"EEF","cpe":[{"product":"gun","vendor":"ninenines"}],"cvss":{"score":6.3,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-346","name":"Origin Validation Error"}],"description":"Origin Validation Error vulnerability in ninenines gun (gun_http2 module) allows cross-origin cookie injection via unvalidated HTTP/2 PUSH_PROMISE authority.\n\nIn gun_http2:push_promise_frame/7, the :authority pseudo-header from an incoming PUSH_PROMISE frame is stored verbatim into the promised stream record without checking that it matches the connection's origin. When gun_http2:headers_frame/9 later processes the response headers for the promised stream, it calls gun_cookies:set_cookie_header/7 with the unvalidated server-supplied authority before any status branching and before user code can act. This violates RFC 7540 §10.6 / RFC 9113 §8.4, which require receivers to treat as a protocol error any push for a resource the server is not authoritative for.\n\nA malicious or compromised HTTP/2 server can plant cookies scoped to arbitrary third-party domains into the client's shared cookie store. This enables session fixation attacks against those domains and, if the planted cookie overrides a legitimate session token, may result in account takeover. No user interaction beyond making a normal HTTP/2 request to the attacker-controlled server is required.\n\nThis issue affects gun: from 2.0.0 before 2.4.0.","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":"gun HTTP/2 PUSH_PROMISE authority not validated against connection origin allows cross-origin cookie injection","id":"CVE-2026-43972","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Hex","product":null,"products":[],"type":"other","year":"2026"},"n_packages":3,"n_references":3,"next":{"headline":"gun HTTP/1.1 response buffer has no size limit allowing server-controlled memory exhaustion","id":"CVE-2026-43973"},"packages":[{"ecosystem":"Hex","fixed":["2.4.0"],"introduced":["2.0.0"],"last_affected":[],"package":"gun","purl":"pkg:hex/gun","source":"EEF-CVE-2026-43972"},{"ecosystem":"Hex","fixed":["2.4.0"],"introduced":["2.0.0"],"last_affected":[],"package":"gun","purl":null,"source":"GHSA-36w4-95hv-5vwg"},{"ecosystem":"Hex","fixed":["2.4.0"],"introduced":["2.0.0"],"last_affected":[],"package":"gun","purl":"pkg:hex/gun","source":"GHSA-36w4-95hv-5vwg"}],"prev":{"headline":"Link Header Directive Smuggling via Unescaped target/rel/Attribute Keys in cow_link:link/1","id":"CVE-2026-43971"},"products":["gun"],"published":"2026-06-08","related":[{"cvss_score":8.7,"headline":"gun HTTP/1.1 response buffer has no size limit allowing server-controlled memory exhaustion","id":"CVE-2026-43973","kev_date_added":null,"published":"2026-06-08"},{"cvss_score":8.7,"headline":"gun HTTP/1.1 client accepts unsolicited 101 Switching Protocols response allowing server-driven protocol hijack and OOM","id":"CVE-2026-43974","kev_date_added":null,"published":"2026-06-08"}],"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":"2026-06-08","vendors":["ninenines"]},"summary":"A malicious HTTP/2 server can inject cookies for arbitrary domains via unvalidated PUSH_PROMISE frames, potentially leading to account takeover.","url":"https://insights.sbomify.com/CVE-2026-43972/"}