{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23077 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23077 is a high-severity use after free vulnerability in Linux kernel, published on 4 Feb 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-2026-23077 and fix it if it is affected.\n\nWhat it is: CVE-2026-23077 is a high-severity use after free vulnerability in Linux kernel, published on 4 Feb 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-2026-23077 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-2026-23077/ (Markdown: https://insights.sbomify.com/CVE-2026-23077/index.md)","id":"CVE-2026-23077","markdown":"https://insights.sbomify.com/CVE-2026-23077/index.md","name":"CVE-2026-23077","record":{"aliases":["BELL-CVE-2026-23077","DEBIAN-CVE-2026-23077","GHSA-jfpv-p5jh-pjp7","UBUNTU-CVE-2026-23077"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A use-after-free vulnerability in the Linux kernel's memory management allows local attackers to execute arbitrary code or escalate privileges via mremap operations.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/vma: fix anon_vma UAF on mremap() faulted, unfaulted merge\n\nPatch series \"mm/vma: fix anon_vma UAF on mremap() faulted, unfaulted\nmerge\", v2.\n\nCommit 879bca0a2c4f (\"mm/vma: fix incorrectly disallowed anonymous VMA\nmerges\") introduced the ability to merge previously unavailable VMA merge\nscenarios.\n\nHowever, it is handling merges incorrectly when it comes to mremap() of a\nfaulted VMA adjacent to an unfaulted VMA.  The issues arise in three\ncases:\n\n1. Previous VMA unfaulted:\n\n              copied -----|\n                          v\n\t|-----------|.............|\n\t| unfaulted |(faulted VMA)|\n\t|-----------|.............|\n\t     prev\n\n2. Next VMA unfaulted:\n\n              copied -----|\n                          v\n\t            |.............|-----------|\n\t            |(faulted VMA)| unfaulted |\n                    |.............|-----------|\n\t\t                      next\n\n3. Both adjacent VMAs unfaulted:\n\n              copied -----|\n                          v\n\t|-----------|.............|-----------|\n\t| unfaulted |(faulted VMA)| unfaulted |\n\t|-----------|.............|-----------|\n\t     prev                      next\n\nThis series fixes each of these cases, and introduces self tests to assert\nthat the issues are corrected.\n\nI also test a further case which was already handled, to assert that my\nchanges continues to correctly handle it:\n\n4. prev unfaulted, next faulted:\n\n              copied -----|\n                          v\n\t|-----------|.............|-----------|\n\t| unfaulted |(faulted VMA)|  faulted  |\n\t|-----------|.............|-----------|\n\t     prev                      next\n\nThis bug was discovered via a syzbot report, linked to in the first patch\nin the series, I confirmed that this series fixes the bug.\n\nI also discovered that we are failing to check that the faulted VMA was\nnot forked when merging a copied VMA in cases 1-3 above, an issue this\nseries also addresses.\n\nI also added self tests to assert that this is resolved (and confirmed\nthat the tests failed prior to this).\n\nI also cleaned up vma_expand() as part of this work, renamed\nvma_had_uncowed_parents() to vma_is_fork_child() as the previous name was\nunduly confusing, and simplified the comments around this function.\n\nThis patch (of 4):\n\nCommit 879bca0a2c4f (\"mm/vma: fix incorrectly disallowed anonymous VMA\nmerges\") introduced the ability to merge previously unavailable VMA merge\nscenarios.\n\nThe key piece of logic introduced was the ability to merge a faulted VMA\nimmediately next to an unfaulted VMA, which relies upon dup_anon_vma() to\ncorrectly handle anon_vma state.\n\nIn the case of the merge of an existing VMA (that is changing properties\nof a VMA and then merging if those properties are shared by adjacent\nVMAs), dup_anon_vma() is invoked correctly.\n\nHowever in the case of the merge of a new VMA, a corner case peculiar to\nmremap() was missed.\n\nThe issue is that vma_expand() only performs dup_anon_vma() if the target\n(the VMA that will ultimately become the merged VMA): is not the next VMA,\ni.e.  the one that appears after the range in which the new VMA is to be\nestablished.\n\nA key insight here is that in all other cases other than mremap(), a new\nVMA merge either expands an existing VMA, meaning that the target VMA will\nbe that VMA, or would have anon_vma be NULL.\n\nSpecifically:\n\n* __mmap_region() - no anon_vma in place, initial mapping.\n* do_brk_flags() - expanding an existing VMA.\n* vma_merge_extend() - expanding an existing VMA.\n* relocate_vma_down() - no anon_vma in place, initial mapping.\n\nIn addition, we are in the unique situation of needing to duplicate\nanon_vma state from a VMA that is neither the previous or next VMA being\nmerged with.\n\ndup_anon_vma() deals exclusively with the target=unfaulted, src=faulted\ncase.  This leaves four possibilities, in each case where the copied VMA\nis faulted:\n\n1. Previous VMA unfaulted:\n\n              copied -----|\n                       \n---truncated---","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":"mm/vma: fix anon_vma UAF on mremap() faulted, unfaulted merge","id":"CVE-2026-23077","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"ALSA: scarlett2: Fix buffer overflow in config retrieval","id":"CVE-2026-23078"},"packages":[],"prev":{"headline":"ALSA: ctxfi: Fix potential OOB access in audio mixer handling","id":"CVE-2026-23076"},"products":["Linux"],"published":"2026-02-04","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":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-08-05","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the Linux kernel's memory management allows local attackers to execute arbitrary code or escalate privileges via mremap operations.","url":"https://insights.sbomify.com/CVE-2026-23077/"}