{"id":"CVE-2026-31676","state":"PUBLISHED","title":"rxrpc: only handle RESPONSE during service challenge","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: only handle RESPONSE during service challenge\n\nOnly process RESPONSE packets while the service connection is still in\nRXRPC_CONN_SERVICE_CHALLENGING. Check that state under state_lock before\nrunning response verification and security initialization, then use a local\nsecured flag to decide whether to queue the secured-connection work after\nthe state transition. This keeps duplicate or late RESPONSE packets from\nre-running the setup path and removes the unlocked post-transition state\ntest.","publishedAt":"2026-04-25T08:46:52.285Z","updatedAt":"2026-10-19T18:56:04.018Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"a1a8efde03a40b6c658d580e96644d9b9a2a0d3a","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"6c3a0fbdafef8316e34ae22333e317a341e737cd","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"0afdfd4941c1b60a1f5c361760daa970edca60cd","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"a6bcf8010af093fe04f7100562e9542ab7882585","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"29b44d904dceb832be880def08b8cb17a0aba91c","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"d0035e634dae83237ab7f5681eb52b2f65d0ceb8","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"03fd2ef73cb4ffd0af100a95b634af54f474414e","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"c43ffdcfdbb5567b1f143556df8a04b4eeea041c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rxrpc/conn_event.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.22","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.22","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.136","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.84","status":"unaffected","lessThanOrEqual":"6.12.*","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/conn_event.c"]}],"references":["https://git.kernel.org/stable/c/a1a8efde03a40b6c658d580e96644d9b9a2a0d3a","https://git.kernel.org/stable/c/6c3a0fbdafef8316e34ae22333e317a341e737cd","https://git.kernel.org/stable/c/0afdfd4941c1b60a1f5c361760daa970edca60cd","https://git.kernel.org/stable/c/a6bcf8010af093fe04f7100562e9542ab7882585","https://git.kernel.org/stable/c/29b44d904dceb832be880def08b8cb17a0aba91c","https://git.kernel.org/stable/c/d0035e634dae83237ab7f5681eb52b2f65d0ceb8","https://git.kernel.org/stable/c/03fd2ef73cb4ffd0af100a95b634af54f474414e","https://git.kernel.org/stable/c/c43ffdcfdbb5567b1f143556df8a04b4eeea041c","https://cert-portal.siemens.com/productcert/html/ssa-784472.html"],"weaknesses":["CWE-362"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31676.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31676","state":"PUBLISHED","datePublished":"2026-04-25T08:46:52.285Z","dateUpdated":"2026-10-19T18:56:04.018Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.130Z"},"containers":{"cna":{"title":"rxrpc: only handle RESPONSE during service challenge","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: only handle RESPONSE during service challenge\n\nOnly process RESPONSE packets while the service connection is still in\nRXRPC_CONN_SERVICE_CHALLENGING. Check that state under state_lock before\nrunning response verification and security initialization, then use a local\nsecured flag to decide whether to queue the secured-connection work after\nthe state transition. This keeps duplicate or late RESPONSE packets from\nre-running the setup path and removes the unlocked post-transition state\ntest."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"a1a8efde03a40b6c658d580e96644d9b9a2a0d3a","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"6c3a0fbdafef8316e34ae22333e317a341e737cd","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"0afdfd4941c1b60a1f5c361760daa970edca60cd","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"a6bcf8010af093fe04f7100562e9542ab7882585","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"29b44d904dceb832be880def08b8cb17a0aba91c","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"d0035e634dae83237ab7f5681eb52b2f65d0ceb8","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"03fd2ef73cb4ffd0af100a95b634af54f474414e","versionType":"git"},{"version":"17926a79320afa9b95df6b977b40cca6d8713cea","status":"affected","lessThan":"c43ffdcfdbb5567b1f143556df8a04b4eeea041c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rxrpc/conn_event.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.22","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.22","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.136","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.84","status":"unaffected","lessThanOrEqual":"6.12.*","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/conn_event.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/a1a8efde03a40b6c658d580e96644d9b9a2a0d3a"},{"url":"https://git.kernel.org/stable/c/6c3a0fbdafef8316e34ae22333e317a341e737cd"},{"url":"https://git.kernel.org/stable/c/0afdfd4941c1b60a1f5c361760daa970edca60cd"},{"url":"https://git.kernel.org/stable/c/a6bcf8010af093fe04f7100562e9542ab7882585"},{"url":"https://git.kernel.org/stable/c/29b44d904dceb832be880def08b8cb17a0aba91c"},{"url":"https://git.kernel.org/stable/c/d0035e634dae83237ab7f5681eb52b2f65d0ceb8"},{"url":"https://git.kernel.org/stable/c/03fd2ef73cb4ffd0af100a95b634af54f474414e"},{"url":"https://git.kernel.org/stable/c/c43ffdcfdbb5567b1f143556df8a04b4eeea041c"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - RxRPC is a UDP-based network protocol, and the vulnerable RESPONSE handling is reached by packets sent to a listening AF_RXRPC service endpoint.\nAC:L - The attacker controls the packet timing and can send duplicate or late RESPONSE packets on a service connection; no uncontrollable race or special memory layout is required to trigger repeated setup processing.\nPR:N - The packet path is reached during the service-side authentication handshake before local privileges are required on the target, and a remote peer can exercise it by sending RxRPC protocol packets to the exposed service.\nUI:N - No victim user action is needed once an RxRPC service is listening; packet processing occurs in the kernel receive path.\nS:U - The impact remains within the kernel and the affected RxRPC service security authority, with no VM, sandbox, or separate security-scope escape.\nC:N - The bug re-runs connection security setup and leaks/replaces connection security objects, but I found no direct information disclosure or arbitrary read primitive.\nI:N - The reachable effect is improper repeated security initialization rather than attacker-controlled memory corruption or arbitrary modification of protected data.\nA:H - Repeated late or duplicate RESPONSE packets can repeatedly allocate and leak connection security state and disrupt/abort RxRPC connections, making kernel or service-level denial of service a reasonable impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:24:23.558Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"6.6.136"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"6.12.84"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"6.18.23"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"6.19.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 TM MFP - GNU/Linux subsystem","defaultStatus":"unknown","versions":[{"version":"0","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:17:45.719Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-31676","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:12:15.479986Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-362","lang":"en","type":"CWE","description":"CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T18:56:04.018Z"}}]}}}