{"id":"CVE-2026-23274","title":"netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels\n\nIDLETIMER revision 0 rules reuse existing timers by label and always call\nmod_timer() on timer->timer.…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44","Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 144f88054ba0180467356f40895bd660b5dceeec","Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 28c7cfaf0c0ab17cbd7754092116fd1af45271f9","Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 54080355999381fed4a26129579a5765bab87491","Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 5e7ece24c5cb75a60402aad4d803c7898ea40aa9","Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1","Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < f228b9ae2a7e84d1153616d8e71c4236cb1f1309","Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf","Linux 5.7"],"published":"2026-03-20","updated":"2026-09-08","sourceUpdated":"2026-09-08T08:45:17.896Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23274","references":[{"url":"https://git.kernel.org/stable/c/32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44"},{"url":"https://git.kernel.org/stable/c/144f88054ba0180467356f40895bd660b5dceeec"},{"url":"https://git.kernel.org/stable/c/28c7cfaf0c0ab17cbd7754092116fd1af45271f9"},{"url":"https://git.kernel.org/stable/c/54080355999381fed4a26129579a5765bab87491"},{"url":"https://git.kernel.org/stable/c/5e7ece24c5cb75a60402aad4d803c7898ea40aa9"},{"url":"https://git.kernel.org/stable/c/f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1"},{"url":"https://git.kernel.org/stable/c/f228b9ae2a7e84d1153616d8e71c4236cb1f1309"},{"url":"https://git.kernel.org/stable/c/329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf"}],"tags":["cve.org"],"epss":0.00167,"epssPercentile":0.06397,"ingestedAt":"2026-09-08T15:33:26.993Z","slug":"CVE-2026-23274","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels\n\nIDLETIMER revision 0 rules reuse existing timers by label and always call\nmod_timer() on timer->timer.\n\nIf the label was created first by revision 1 with XT_IDLETIMER_ALARM,\nthe object uses alarm timer semantics and timer->timer is never initialized.\nReusing that object from revision 0 causes mod_timer() on an uninitialized\ntimer_list, triggering debugobjects warnings and possible panic when\npanic_on_warn=1.\n\nFix this by rejecting revision 0 rule insertion when an existing timer with\nthe same label is of ALARM type.\n\n## Affected\n\n- `Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44`\n- `Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 144f88054ba0180467356f40895bd660b5dceeec`\n- `Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 28c7cfaf0c0ab17cbd7754092116fd1af45271f9`\n- `Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 54080355999381fed4a26129579a5765bab87491`\n- `Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 5e7ece24c5cb75a60402aad4d803c7898ea40aa9`\n- `Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1`\n- `Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < f228b9ae2a7e84d1153616d8e71c4236cb1f1309`\n- `Linux >= 68983a354a655c35d3fb204489d383a2a051fda7 < 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf`\n- `Linux 5.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}