{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-31657 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-31657 is a critical use after free vulnerability in Linux kernel, published on 24 Apr 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-2026-31657 and fix it if it is affected.\n\nWhat it is: CVE-2026-31657 is a critical use after free vulnerability in Linux kernel, published on 24 Apr 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-2026-31657 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-2026-31657/ (Markdown: https://insights.sbomify.com/CVE-2026-31657/index.md)","id":"CVE-2026-31657","markdown":"https://insights.sbomify.com/CVE-2026-31657/index.md","name":"CVE-2026-31657","record":{"aliases":["AZL-83810","BELL-CVE-2026-31657","DEBIAN-CVE-2026-31657","GHSA-w24x-3wrx-8q34","ROOT-OS-DEBIAN-11-CVE-2026-31657","ROOT-OS-DEBIAN-12-CVE-2026-31657","ROOT-OS-UBUNTU-2204-CVE-2026-31657","ROOT-OS-UBUNTU-2404-CVE-2026-31657","UBUNTU-CVE-2026-31657"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel module","requires_auth":"none","summary":"A use-after-free vulnerability in the batman-adv kernel module allows attackers to cause a denial of service or potentially execute code via improper reference handling.","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":9.8,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-476","name":"NULL Pointer Dereference"},{"id":"CWE-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: hold claim backbone gateways by reference\n\nbatadv_bla_add_claim() can replace claim-\u003ebackbone_gw and drop the old\ngateway's last reference while readers still follow the pointer.\n\nThe netlink claim dump path dereferences claim-\u003ebackbone_gw-\u003eorig and\ntakes claim-\u003ebackbone_gw-\u003ecrc_lock without pinning the underlying\nbackbone gateway. batadv_bla_check_claim() still has the same naked\npointer access pattern.\n\nReuse batadv_bla_claim_get_backbone_gw() in both readers so they operate\non a stable gateway reference until the read-side work is complete.\nThis keeps the dump and claim-check paths aligned with the lifetime\nrules introduced for the other BLA claim readers.","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":"batman-adv: hold claim backbone gateways by reference","id":"CVE-2026-31657","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":8,"next":{"headline":"net: altera-tse: fix skb leak on DMA mapping error in tse_start_xmit()","id":"CVE-2026-31658"},"packages":[],"prev":{"headline":"drm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat","id":"CVE-2026-31656"},"products":["Linux"],"published":"2026-04-24","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":"yes","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the batman-adv kernel module allows attackers to cause a denial of service or potentially execute code via improper reference handling.","url":"https://insights.sbomify.com/CVE-2026-31657/"}