{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-90261 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-90261 is a denial of service vulnerability in Linux, published on 17 Sep 2026. 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-2026-90261 and fix it if it is affected.\n\nWhat it is: CVE-2026-90261 is a denial of service vulnerability in Linux, published on 17 Sep 2026. 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-2026-90261 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-2026-90261/ (Markdown: https://insights.sbomify.com/CVE-2026-90261/index.md)","id":"CVE-2026-90261","markdown":"https://insights.sbomify.com/CVE-2026-90261/index.md","name":"CVE-2026-90261","record":{"aliases":["AZL-102258","BELL-CVE-2026-90261","DEBIAN-CVE-2026-90261","GHSA-6683-vc4x-94r5","UBUNTU-CVE-2026-90261"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"none","summary":"A flaw in the Linux kernel's btrfs zoned filesystem can cause a deadlock and force the filesystem read-only during metadata-heavy operations, requiring local access.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zoned: flush active metadata block group at btree_writepages() start\n\nbtree_writepages() writes the btree inode's dirty metadata in ascending\nlogical address order. On a zoned filesystem only one metadata and one\nsystem block group is active for writing at a time, and\ncheck_bg_is_active() (via btrfs_check_meta_write_pointer()) pivots the\nactive block group as writeback moves from one block group to the next.\n\nIf the active block group sits at a higher logical address than another\nblock group that also holds dirty metadata, the ascending walk reaches\nthe lower one first and, to write it, has to finish the active block\ngroup and activate the lower one. It cannot finish a block group that\nstill has unsent IO, and during WB_SYNC_ALL \u0026\u0026 !for_sync (commit)\nwriteback it deliberately refuses to wait for that IO under\nfs_info-\u003ezoned_meta_io_lock, as that can deadlock. The pivot thus cannot\nissue the submission itself either, so it gives up:\nbtrfs_check_meta_write_pointer() returns -EAGAIN, which\nbtrfs_write_and_wait_transaction() treats as fatal and aborts the\ntransaction, forcing the filesystem read-only. This happens\nintermittently under metadata-heavy relocation (e.g. fstests btrfs/187).\n\nFlush the active metadata and system block groups at the start of\nbtree_writepages(), under the fs_info-\u003ezoned_meta_io_lock it already\nholds, so they have no unsent IO left and the later pivot can finish\nthem and make forward progress.","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":"btrfs: zoned: flush active metadata block group at btree_writepages() start","id":"CVE-2026-90261","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"btrfs: retry verity reads for not-uptodate Merkle folios","id":"CVE-2026-90262"},"packages":[],"prev":{"headline":"btrfs: zoned: don't clobber the extent buffer when zeroing it out","id":"CVE-2026-90260"},"products":["Linux"],"published":"2026-09-17","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A flaw in the Linux kernel's btrfs zoned filesystem can cause a deadlock and force the filesystem read-only during metadata-heavy operations, requiring local access.","url":"https://insights.sbomify.com/CVE-2026-90261/"}