{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21691 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21691 is a medium-severity vulnerability in Linux kernel, published on 10 Feb 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-2025-21691 and fix it if it is affected.\n\nWhat it is: CVE-2025-21691 is a medium-severity vulnerability in Linux kernel, published on 10 Feb 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-2025-21691 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-2025-21691/ (Markdown: https://insights.sbomify.com/CVE-2025-21691/index.md)","id":"CVE-2025-21691","markdown":"https://insights.sbomify.com/CVE-2025-21691/index.md","name":"CVE-2025-21691","record":{"aliases":["BELL-CVE-2025-21691","DEBIAN-CVE-2025-21691","GHSA-3m25-8xh3-c6p2","UBUNTU-CVE-2025-21691"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["data_read"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"Local attackers can read page cache statistics for files they do not own or have write access to, bypassing intended permission checks.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncachestat: fix page cache statistics permission checking\n\nWhen the 'cachestat()' system call was added in commit cf264e1329fb\n(\"cachestat: implement cachestat syscall\"), it was meant to be a much\nmore convenient (and performant) version of mincore() that didn't need\nmapping things into the user virtual address space in order to work.\n\nBut it ended up missing the \"check for writability or ownership\" fix for\nmincore(), done in commit 134fca9063ad (\"mm/mincore.c: make mincore()\nmore conservative\").\n\nThis just adds equivalent logic to 'cachestat()', modified for the file\ncontext (rather than vma).","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":"cachestat: fix page cache statistics permission checking","id":"CVE-2025-21691","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"information_disclosure","year":"2025"},"n_packages":0,"n_references":4,"next":{"headline":"net: sched: fix ets qdisc OOB Indexing","id":"CVE-2025-21692"},"packages":[],"prev":{"headline":"scsi: storvsc: Ratelimit warning logs to prevent VM denial of service","id":"CVE-2025-21690"},"products":["Linux"],"published":"2025-02-10","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":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"Local attackers can read page cache statistics for files they do not own or have write access to, bypassing intended permission checks.","url":"https://insights.sbomify.com/CVE-2025-21691/"}