{"id":"CVE-2026-31640","summary":"rxrpc: Fix use of wrong skb when comparing queued RESP challenge serial","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix use of wrong skb when comparing queued RESP challenge serial\n\nIn rxrpc_post_response(), the code should be comparing the challenge serial\nnumber from the cached response before deciding to switch to a newer\nresponse, but looks at the newer packet private data instead, rendering the\ncomparison always false.\n\nFix this by switching to look at the older packet.\n\nFix further[1] to substitute the new packet in place of the old one if\nnewer and also to release whichever we don't use.","modified":"2026-07-08T07:01:43.211570398Z","published":"2026-04-24T14:44:54.024Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31640.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/20386e7f8d97475b8d815873e246423317ec4260"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9132b1a7bf83b4a8042fffbc99d075b727a16742"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b33f5741bb187db8ff32e8f5b96def77cc94dfca"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31640.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31640"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5800b1cf3fd8ccab752a101865be1e76dac33142"},{"fixed":"9132b1a7bf83b4a8042fffbc99d075b727a16742"},{"fixed":"20386e7f8d97475b8d815873e246423317ec4260"},{"fixed":"b33f5741bb187db8ff32e8f5b96def77cc94dfca"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31640.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.18.23"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.13"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31640.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}