{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21639 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21639 is a medium-severity vulnerability in Linux kernel, published on 19 Jan 2025. 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-2025-21639 and fix it if it is affected.\n\nWhat it is: CVE-2025-21639 is a medium-severity vulnerability in Linux kernel, published on 19 Jan 2025. 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-2025-21639 in the wild and no public exploit code.\n\nAffected product: Linux kernel. 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-2025-21639/ (Markdown: https://insights.sbomify.com/CVE-2025-21639/index.md)","id":"CVE-2025-21639","markdown":"https://insights.sbomify.com/CVE-2025-21639/index.md","name":"CVE-2025-21639","record":{"aliases":["AZL-57225","BELL-CVE-2025-21639","DEBIAN-CVE-2025-21639","GHSA-6w8c-3g24-p9jh","UBUNTU-CVE-2025-21639"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A null pointer dereference in the Linux kernel SCTP subsystem can cause a system crash when specific network namespace conditions are met.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"cisa-adp","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: sysctl: rto_min/max: avoid using current-\u003ensproxy\n\nAs mentioned in a previous commit of this series, using the 'net'\nstructure via 'current' is not recommended for different reasons:\n\n- Inconsistency: getting info from the reader's/writer's netns vs only\n  from the opener's netns.\n\n- current-\u003ensproxy can be NULL in some cases, resulting in an 'Oops'\n  (null-ptr-deref), e.g. when the current task is exiting, as spotted by\n  syzbot [1] using acct(2).\n\nThe 'net' structure can be obtained from the table-\u003edata using\ncontainer_of().\n\nNote that table-\u003edata could also be used directly, as this is the only\nmember needed from the 'net' structure, but that would increase the size\nof this fix, to use '*data' everywhere 'net-\u003esctp.rto_min/max' is used.","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":"sctp: sysctl: rto_min/max: avoid using current-\u003ensproxy","id":"CVE-2025-21639","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2025"},"n_packages":0,"n_references":7,"next":{"headline":"sctp: sysctl: cookie_hmac_alg: avoid using current-\u003ensproxy","id":"CVE-2025-21640"},"packages":[],"prev":{"headline":"sctp: sysctl: auth_enable: avoid using current-\u003ensproxy","id":"CVE-2025-21638"},"products":["Linux"],"published":"2025-01-19","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A null pointer dereference in the Linux kernel SCTP subsystem can cause a system crash when specific network namespace conditions are met.","url":"https://insights.sbomify.com/CVE-2025-21639/"}