{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-89551 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-89551 is a critical vulnerability in Linux, published on 11 Sep 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-2026-89551 and fix it if it is affected.\n\nWhat it is: CVE-2026-89551 is a critical vulnerability in Linux, published on 11 Sep 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-2026-89551 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-2026-89551/ (Markdown: https://insights.sbomify.com/CVE-2026-89551/index.md)","id":"CVE-2026-89551","markdown":"https://insights.sbomify.com/CVE-2026-89551/index.md","name":"CVE-2026-89551","record":{"aliases":["AZL-100338","BELL-CVE-2026-89551","DEBIAN-CVE-2026-89551","GHSA-7gqj-379q-cvhq","UBUNTU-CVE-2026-89551"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","other"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel SUNRPC","requires_auth":"none","summary":"An integer underflow in the Linux kernel SUNRPC module can cause buffer length corruption, potentially leading to denial of service or memory safety issues.","user_interaction":"not_required","vuln_class":"integer_overflow"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"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":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: xdr_buf_trim: clamp buf-\u003elen to avoid underflow\n\nxdr_buf_trim() trims `len` bytes from the tail of an xdr_buf by\nwalking the tail, pages, and head iovecs.  Each per-section step\nuses min_t() so it never removes more bytes than that section\nholds, but the final accounting at the fix_len label subtracts the\ntotal bytes actually consumed from buf-\u003elen without any clamp:\n\n    fix_len:\n            buf-\u003elen -= (len - trim);\n\nWhen the caller has set buf-\u003elen to a value smaller than the sum\nof the iov_lens, (len - trim) can exceed buf-\u003elen and the unsigned\nsubtraction wraps to near UINT_MAX.  gss_krb5_unwrap_v2() reaches\nxdr_buf_trim() in exactly that state:\n\n    buf-\u003ehead[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip;\n    buf-\u003elen = len - (GSS_KRB5_TOK_HDR_LEN + headskip);\n    xdr_buf_trim(buf, ec + GSS_KRB5_TOK_HDR_LEN + tailskip);\n\nbuf-\u003elen is a small wire-derived value while the iov_lens are at\npage scale, so the per-section loops legitimately consume far more\nbytes than buf-\u003elen records.  The wrapped buf-\u003elen then propagates\nas the authoritative stream bound into every downstream XDR\ndecoder.\n\nFix by clamping the decrement so buf-\u003elen bottoms out at zero:\n\n    buf-\u003elen -= min_t(unsigned int, buf-\u003elen, len - trim);\n\nOn the normal path where the iov_lens sum to buf-\u003elen, (len - trim)\nis always \u003c= buf-\u003elen and the result is identical to before.  No\ncallers change behavior outside the underflow case.","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":"SUNRPC: xdr_buf_trim: clamp buf-\u003elen to avoid underflow","id":"CVE-2026-89551","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"integer_overflow","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"params: fix charp corruption on allocation failure","id":"CVE-2026-89552"},"packages":[],"prev":{"headline":"SUNRPC: svcauth_gss: enforce krb5 token minimum length","id":"CVE-2026-89550"},"products":["Linux"],"published":"2026-09-11","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"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":"An integer underflow in the Linux kernel SUNRPC module can cause buffer length corruption, potentially leading to denial of service or memory safety issues.","url":"https://insights.sbomify.com/CVE-2026-89551/"}