{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-53391 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-53391 is a high-severity vulnerability in Linux kernel, published on 19 Jul 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-2026-53391 and fix it if it is affected.\n\nWhat it is: CVE-2026-53391 is a high-severity vulnerability in Linux kernel, published on 19 Jul 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-2026-53391 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-2026-53391/ (Markdown: https://insights.sbomify.com/CVE-2026-53391/index.md)","id":"CVE-2026-53391","markdown":"https://insights.sbomify.com/CVE-2026-53391/index.md","name":"CVE-2026-53391","record":{"aliases":["BELL-CVE-2026-53391","DEBIAN-CVE-2026-53391","GHSA-72jx-g4pr-67hm","ROOT-OS-DEBIAN-11-CVE-2026-53391","ROOT-OS-UBUNTU-2204-CVE-2026-53391","UBUNTU-CVE-2026-53391"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel NFS","requires_auth":"none","summary":"A malicious NFS metadata server can cause a kernel crash in Linux NFS clients by sending a zero-length address in a GETDEVICEINFO response.","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":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/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\nNFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr\n\nnfs4_decode_mp_ds_addr() decodes the r_netid and r_addr opaques of a\nnetaddr4 from a GETDEVICEINFO multipath-DS body, then immediately\ncalls strrchr(buf, '.') to locate the port separator. Both decodes\nuse xdr_stream_decode_string_dup(), and the current code checks only\n\"nlen \u003c 0\" / \"rlen \u003c 0\" before dereferencing the returned string.\n\nWhen the on-wire opaque has length zero, xdr_stream_decode_opaque_inline()\nreturns 0 and xdr_stream_decode_string_dup() falls through to its\n\"*str = NULL; return ret\" tail, leaving buf NULL with a return value\nof 0. The \"\u003c 0\" check does not catch this, and the next line is\nstrrchr(NULL, '.'), a kernel NULL pointer dereference reachable from\nany pNFS-flexfile client mounted against a malicious or compromised\nmetadata server.\n\nReject the zero-length cases explicitly so the decoder fails with\n-EBADMSG (treated as a malformed GETDEVICEINFO body) instead of\npanicking the client.","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":"NFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr","id":"CVE-2026-53391","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":7,"next":{"headline":"NFSv4/flexfiles: reject zero filehandle version count","id":"CVE-2026-53392"},"packages":[],"prev":{"headline":"ksmbd: fix out-of-bounds read in smb_check_perm_dacl()","id":"CVE-2026-53390"},"products":["Linux"],"published":"2026-07-19","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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A malicious NFS metadata server can cause a kernel crash in Linux NFS clients by sending a zero-length address in a GETDEVICEINFO response.","url":"https://insights.sbomify.com/CVE-2026-53391/"}