{"id":"CVE-2026-31631","state":"PUBLISHED","title":"rxrpc: Fix buffer overread in rxgk_do_verify_authenticator()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix buffer overread in rxgk_do_verify_authenticator()\n\nFix rxgk_do_verify_authenticator() to check the buffer size before checking\nthe nonce.","publishedAt":"2026-04-24T14:44:47.305Z","updatedAt":"2026-10-19T18:56:00.756Z","severity":{"score":8.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"794586789800b16dcbe235452494f4223ac80413","versionType":"git"},{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"1c4422d8be81718ecb15d79aedff607323085201","versionType":"git"},{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"f564af387c8c28238f8ebc13314c589d7ba8475d","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/794586789800b16dcbe235452494f4223ac80413","https://git.kernel.org/stable/c/1c4422d8be81718ecb15d79aedff607323085201","https://git.kernel.org/stable/c/f564af387c8c28238f8ebc13314c589d7ba8475d"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31631.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31631","state":"PUBLISHED","datePublished":"2026-04-24T14:44:47.305Z","dateUpdated":"2026-10-19T18:56:00.756Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.125Z"},"containers":{"cna":{"title":"rxrpc: Fix buffer overread in rxgk_do_verify_authenticator()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix buffer overread in rxgk_do_verify_authenticator()\n\nFix rxgk_do_verify_authenticator() to check the buffer size before checking\nthe nonce."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"794586789800b16dcbe235452494f4223ac80413","versionType":"git"},{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"1c4422d8be81718ecb15d79aedff607323085201","versionType":"git"},{"version":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a","status":"affected","lessThan":"f564af387c8c28238f8ebc13314c589d7ba8475d","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/794586789800b16dcbe235452494f4223ac80413"},{"url":"https://git.kernel.org/stable/c/1c4422d8be81718ecb15d79aedff607323085201"},{"url":"https://git.kernel.org/stable/c/f564af387c8c28238f8ebc13314c589d7ba8475d"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H","baseScore":8.2,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - RxRPC is carried over UDP and the vulnerable server-side RXGK RESPONSE processing is reached from received network packets on an AF_RXRPC service endpoint.\nAC:L - There is no race or condition outside the attacker's control once an RXGK-capable service and enctype are in use; a crafted short decrypted authenticator deterministically reaches the missing length check.\nPR:N - The vulnerable code runs during the RXGK authentication handshake before the service connection is accepted. No local privilege on the target is required by a remote peer sending the RESPONSE packet.\nUI:N - No victim user action is required after the RxRPC service is listening; packet processing occurs in the kernel receive path.\nS:U - The impact is confined to the kernel/service host processing the RxRPC connection and does not cross a VM, IOMMU, or comparable security boundary.\nC:L - The bug is a bounded buffer overread of a few bytes past the decrypted authenticator buffer, potentially exposing adjacent kernel heap data through comparison/error behavior. It does not provide an arbitrary kernel memory read.\nI:N - The flaw is an out-of-bounds read before nonce/appdata parsing and does not write attacker-controlled data or corrupt memory.\nA:H - The out-of-bounds read can fault or trigger hardened/debug slab checks, producing a kernel oops or panic. A remote peer can repeatedly send crafted RESPONSE packets."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:23:57.537Z"},"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-2026-31631","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:11:20.356548Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T18:56:00.756Z"}}]}}}