{"answers":{"affected":"3 open source packages ship an affected version, including gun. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-43973 in the wild and no public exploit code.","fix":"Upgrade gun to 2.4.0 or later.","what":"CVE-2026-43973 is a high-severity denial of service 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-2026-43973 and fix it if it is affected.\n\nWhat it is: CVE-2026-43973 is a high-severity denial of service 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-2026-43973 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- gun (Hex): affected from 1.0.0; fixed in 2.4.0\n- gun (Hex): affected from 1.0.0; fixed in 2.4.0\n- gun (Hex): affected from 1.0.0; 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-2026-43973/ (Markdown: https://insights.sbomify.com/CVE-2026-43973/index.md)","id":"CVE-2026-43973","markdown":"https://insights.sbomify.com/CVE-2026-43973/index.md","name":"CVE-2026-43973","record":{"aliases":["AZL-90141","EEF-CVE-2026-43973","GHSA-r53j-fjj5-mv77"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Erlang HTTP client","requires_auth":"none","summary":"A malicious server can exhaust client memory by sending incomplete HTTP responses, causing a node-wide crash in the gun library.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"EEF","cpe":[{"product":"gun","vendor":"ninenines"}],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"}],"description":"Uncontrolled Resource Consumption vulnerability in ninenines gun (gun_http module) allows a malicious server to exhaust client memory via unbounded HTTP/1.1 response buffering.\n\nIn gun_http:handle/5, three clauses accumulate incoming TCP data into the connection's buffer field using binary concatenation with no upper-bound check: the head clause appends data until the \\r\\n\\r\\n header terminator is found; the body_chunked clause appends data whenever cow_http_te:stream_chunked/2 returns a more result indicating an incomplete chunk boundary; and the body_trailer clause appends data until the trailing \\r\\n\\r\\n is found. In each case, when the expected terminator never arrives, the enlarged binary is stored back into state and the process waits for more data, with no configurable or hard-coded ceiling on buffer size.\n\nA malicious or compromised server can exploit this by sending a partial response that never completes. For example, a response may begin with HTTP/1.1 200 OK\\r\\nX-Pad:  followed by an unbounded stream of arbitrary bytes, never sending the header terminator. The gun connection process will continuously append the incoming data to its buffer, causing unbounded heap growth. Because BEAM imposes no per-process heap limit by default, a single malicious connection can exhaust all available memory on the node, causing a node-wide out-of-memory crash.\n\nThis issue affects gun: from 1.0.0 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/1.1 response buffer has no size limit allowing server-controlled memory exhaustion","id":"CVE-2026-43973","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Hex","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":3,"n_references":3,"next":{"headline":"gun HTTP/1.1 client accepts unsolicited 101 Switching Protocols response allowing server-driven protocol hijack and OOM","id":"CVE-2026-43974"},"packages":[{"ecosystem":"Hex","fixed":["2.4.0"],"introduced":["1.0.0"],"last_affected":[],"package":"gun","purl":"pkg:hex/gun","source":"EEF-CVE-2026-43973"},{"ecosystem":"Hex","fixed":["2.4.0"],"introduced":["1.0.0"],"last_affected":[],"package":"gun","purl":null,"source":"GHSA-r53j-fjj5-mv77"},{"ecosystem":"Hex","fixed":["2.4.0"],"introduced":["1.0.0"],"last_affected":[],"package":"gun","purl":"pkg:hex/gun","source":"GHSA-r53j-fjj5-mv77"}],"prev":{"headline":"gun HTTP/2 PUSH_PROMISE authority not validated against connection origin allows cross-origin cookie injection","id":"CVE-2026-43972"},"products":["gun"],"published":"2026-06-08","related":[{"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"},{"cvss_score":6.3,"headline":"gun HTTP/2 PUSH_PROMISE authority not validated against connection origin allows cross-origin cookie injection","id":"CVE-2026-43972","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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-06-08","vendors":["ninenines"]},"summary":"A malicious server can exhaust client memory by sending incomplete HTTP responses, causing a node-wide crash in the gun library.","url":"https://insights.sbomify.com/CVE-2026-43973/"}