{"id":"CVE-2026-31633","state":"PUBLISHED","title":"rxrpc: Fix integer overflow in rxgk_verify_response()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix integer overflow in rxgk_verify_response()\n\nIn rxgk_verify_response(), there's a potential integer overflow due to\nrounding up token_len before checking it, thereby allowing the length check to\nbe bypassed.\n\nFix this by checking the unrounded value against len too (len is limited as\nthe response must fit in a single UDP packet).","publishedAt":"2026-04-24T14:44:48.621Z","updatedAt":"2026-10-19T18:56:00.901Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"1f864d9daaf622aeaa774404fd51e7d6a435b046","versionType":"git"},{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"c1e242beb6b1efc3c286f617e8d940c8fbf2ed41","versionType":"git"},{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"699e52180f4231c257821c037ed5c99d5eb0edb8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rxrpc/rxgk.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.23","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.13","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rxrpc/rxgk.c"]}],"references":["https://git.kernel.org/stable/c/1f864d9daaf622aeaa774404fd51e7d6a435b046","https://git.kernel.org/stable/c/c1e242beb6b1efc3c286f617e8d940c8fbf2ed41","https://git.kernel.org/stable/c/699e52180f4231c257821c037ed5c99d5eb0edb8"],"weaknesses":["CWE-190"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31633.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31633","state":"PUBLISHED","datePublished":"2026-04-24T14:44:48.621Z","dateUpdated":"2026-10-19T18:56:00.901Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.125Z"},"containers":{"cna":{"title":"rxrpc: Fix integer overflow in rxgk_verify_response()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix integer overflow in rxgk_verify_response()\n\nIn rxgk_verify_response(), there's a potential integer overflow due to\nrounding up token_len before checking it, thereby allowing the length check to\nbe bypassed.\n\nFix this by checking the unrounded value against len too (len is limited as\nthe response must fit in a single UDP packet)."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"1f864d9daaf622aeaa774404fd51e7d6a435b046","versionType":"git"},{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"c1e242beb6b1efc3c286f617e8d940c8fbf2ed41","versionType":"git"},{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"699e52180f4231c257821c037ed5c99d5eb0edb8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rxrpc/rxgk.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.23","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.13","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rxrpc/rxgk.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/1f864d9daaf622aeaa774404fd51e7d6a435b046"},{"url":"https://git.kernel.org/stable/c/c1e242beb6b1efc3c286f617e8d940c8fbf2ed41"},{"url":"https://git.kernel.org/stable/c/699e52180f4231c257821c037ed5c99d5eb0edb8"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - rxgk_verify_response() is reached by a remote RxRPC RESPONSE packet over UDP on a listening RxRPC service using YFS-RxGK security.\nAC:L - The attacker controls the RESPONSE packet fields needed to trigger the integer overflow; no race or condition outside attacker control is required.\nPR:N - The vulnerable parsing occurs during the service-side challenge/response handshake before the RESPONSE authenticator is verified, so no authenticated credentials are required.\nUI:N - No victim user action is required once an affected RxRPC service is listening and reachable.\nS:U - The impact is within the kernel/RxRPC service security authority and does not cross a separate sandbox, VM, or hardware boundary.\nC:H - The overflow can cause subsequent token/authenticator parsing and crypto scatterlist construction to operate on attacker-controlled impossible lengths, creating out-of-bounds memory access potential.\nI:H - The affected decryption path operates in place over scatterlists derived from corrupted lengths, making kernel memory corruption and control-flow-relevant modification defensible.\nA:H - Related oversized RxGK RESPONSE length paths reach skb_to_sgvec() BUG_ON(len), and this overflow can similarly drive impossible lengths, causing a remote kernel crash."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:23:58.581Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.23"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.19.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-31633","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:11:22.560304Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-190","lang":"en","type":"CWE","description":"CWE-190 Integer Overflow or Wraparound"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T18:56:00.901Z"}}]}}}