{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-63913 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-63913 is a high-severity denial of service vulnerability in Linux, published on 19 Jul 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-2026-63913 and fix it if it is affected.\n\nWhat it is: CVE-2026-63913 is a high-severity denial of service vulnerability in Linux, published on 19 Jul 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-2026-63913 in the wild and no public exploit code.\n\nAffected product: Linux. 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-2026-63913/ (Markdown: https://insights.sbomify.com/CVE-2026-63913/index.md)","id":"CVE-2026-63913","markdown":"https://insights.sbomify.com/CVE-2026-63913/index.md","name":"CVE-2026-63913","record":{"aliases":["BELL-CVE-2026-63913","DEBIAN-CVE-2026-63913","GHSA-8577-pmm3-chq2","ROOT-OS-UBUNTU-2204-CVE-2026-63913","UBUNTU-CVE-2026-63913"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"Attackers can prematurely terminate active NAT connections by sending crafted RST packets, causing denial of service in the Linux kernel.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":8.2,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","version":"3.1"},"cwes":[{"id":"CWE-20","name":"Improper Input Validation"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: tcp: do not force CLOSE on invalid-seq RST without direction check\n\nAn unintended behavior in the TCP conntrack state machine allows a\nconnection to be forced into the CLOSE state using an RST packet with an\ninvalid sequence number.\n\nSpecifically, after a SYN packet is observed, an RST with an invalid SEQ\ncan transition the conntrack entry to TCP_CONNTRACK_CLOSE, regardless of\nwhether the RST corresponds to the expected reply direction. The relevant\ncode path assumes the RST is a response to an outgoing SYN, but does not\nvalidate packet direction or ensure that a matching SYN was actually sent\nin the opposite direction.\n\nAs a result, a crafted packet sequence consisting of a SYN followed by an\ninvalid-sequence RST can prematurely terminate an active NAT entry. This\nmakes connection teardown easier than intended.\n\nSo, tighten the state transition logic to ensure that RST-triggered\nCLOSE transitions only occur when the RST is a valid response to a\npreviously observed SYN in the correct direction.","ecosystems":[],"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":"netfilter: conntrack: tcp: do not force CLOSE on invalid-seq RST without direction check","id":"CVE-2026-63913","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"xfrm: route MIGRATE notifications to caller's netns","id":"CVE-2026-63914"},"packages":[],"prev":{"headline":"xfrm: esp: restore combined single-frag length gate","id":"CVE-2026-63912"},"products":["Linux"],"published":"2026-07-19","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"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":"2026-10-19","vendors":["Linux"]},"summary":"Attackers can prematurely terminate active NAT connections by sending crafted RST packets, causing denial of service in the Linux kernel.","url":"https://insights.sbomify.com/CVE-2026-63913/"}