{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74425","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.894Z","datePublished":"2026-08-15T05:59:27.806Z","dateUpdated":"2026-08-17T05:47:00.844Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:47:00.844Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nafs: handle CB.InitCallBackState3 requests without a server record\n\nThe cache manager callback path now attaches the server record to an\nincoming call through the rxrpc peer's app data.  That association is\nnot guaranteed to exist for every callback request, and most callback\nhandlers already tolerate that case.\n\nMake CB.InitCallBackState3 follow the same pattern by checking whether a\nserver record was attached before using it.  If the peer is not mapped\nto a server record, trace the request and ignore it, matching the\nexisting behaviour for other unmatched callback requests.\n\nThis keeps the callback handler consistent with the rest of the cache\nmanager service and avoids depending on peer state that may not be\navailable for a given request."}],"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 - The bug is in the AFS cache-manager callback handler reached from remote RXRPC/UDP traffic on the CM listener (port 7001). Packets are processed via rxrpc_new_incoming_call() -> afs_deliver_cm_op_id() -> afs_deliver_cb_init_call_back_state3() without any local syscall.\nAC:L - Once AFS is loaded, an attacker can reliably trigger the NULL server path by sending a CB.InitCallBackState3 (opcode 213) from an unmapped peer; call->server is only set from rxrpc peer app data in afs_rx_new_call() and may legitimately be NULL.\nPR:N - Exploitation requires no Linux privileges on the victim. The callback socket accepts remote RXRPC connections without local capability checks, and incoming connections with security index 0 bypass the challenge handshake, so no authenticated local user is needed.\nUI:N - No victim user action is required beyond the system already running the AFS client module with its callback socket open; the crash is caused entirely by attacker-sent network packets.\nS:U - Impact is a kernel NULL pointer dereference and resulting oops/panic within kernel context. This is a standard kernel denial-of-service and does not cross a security boundary such as VM escape or sandbox breakout.\nC:N - The failure is a NULL pointer dereference in memcmp(call->request, &call->server->_uuid, ...) when call->server is NULL. This is a pure crash with no out-of-bounds read, use-after-free, or information disclosure primitive.\nI:N - The vulnerability does not modify kernel or user data; it dereferences a NULL server pointer during UUID comparison. There is no memory corruption, arbitrary write, or code execution primitive.\nA:H - Dereferencing call->server when it is NULL causes a kernel fault in the AFS async RXRPC workqueue path, producing an oops or panic and denying all system availability until reboot."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/afs/cmservice.c"],"versions":[{"version":"39ba6af83a7f9dee3e6a7916f41a48bcbda54eba","lessThan":"42e3917cdbdc3d35e191c525687a6d5427f237fd","status":"affected","versionType":"git"},{"version":"40e8b52fe8c8ab6920ea5f59c5469b6918cce624","lessThan":"cc848a080f7a6848dfeef441722419fdcbfe9b8d","status":"affected","versionType":"git"},{"version":"40e8b52fe8c8ab6920ea5f59c5469b6918cce624","lessThan":"0bd5f2786a878148190b4c7c259d01313d5f2357","status":"affected","versionType":"git"},{"version":"40e8b52fe8c8ab6920ea5f59c5469b6918cce624","lessThan":"f3cf725cd284b7912d5522babb44721bf38c8887","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/afs/cmservice.c"],"versions":[{"version":"6.15","status":"affected"},{"version":"0","lessThan":"6.15","status":"unaffected","versionType":"semver"},{"version":"6.18.40","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.5","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/42e3917cdbdc3d35e191c525687a6d5427f237fd"},{"url":"https://git.kernel.org/stable/c/cc848a080f7a6848dfeef441722419fdcbfe9b8d"},{"url":"https://git.kernel.org/stable/c/0bd5f2786a878148190b4c7c259d01313d5f2357"},{"url":"https://git.kernel.org/stable/c/f3cf725cd284b7912d5522babb44721bf38c8887"}],"title":"afs: handle CB.InitCallBackState3 requests without a server record","x_generator":{"engine":"bippy-1.2.0"}}}}