Answer in brief
CVE-2026-23274 records a High severity (CVSS 7.8) vulnerability in netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-23274 records a High severity (CVSS 7.8) vulnerability in netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=68983a354a655c35d3fb204489d383a2a051fda7 <32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44 || >=68983a354a655c35d3fb204489d383a2a051fda7 <144f88054ba0180467356f40895bd660b5dceeec || >=68983a354a655c35d3fb204489d383a2a051fda7 <28c7cfaf0c0ab17cbd7754092116fd1af45271f9 || >=68983a354a655c35d3fb204489d383a2a051fda7 <54080355999381fed4a26129579a5765bab87491 || >=68983a354a655c35d3fb204489d383a2a051fda7 <5e7ece24c5cb75a60402aad4d803c7898ea40aa9 || >=68983a354a655c35d3fb204489d383a2a051fda7 <f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1 || >=68983a354a655c35d3fb204489d383a2a051fda7 <f228b9ae2a7e84d1153616d8e71c4236cb1f1309 || >=68983a354a655c35d3fb204489d383a2a051fda7 <329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf | 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44, 144f88054ba0180467356f40895bd660b5dceeec, 28c7cfaf0c0ab17cbd7754092116fd1af45271f9, 54080355999381fed4a26129579a5765bab87491, 5e7ece24c5cb75a60402aad4d803c7898ea40aa9, f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1, f228b9ae2a7e84d1153616d8e71c4236cb1f1309, 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf |
| Linux/Linuxgeneric | 5.7 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Mar 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels IDLETIMER revision 0 rules reuse existing timers by label and always call mod_timer() on timer->timer. If the label was created first by revision 1 with XT_IDLETIMER_ALARM, the object uses alarm timer semantics and timer->timer is never initialized. Reusing that object from revision 0 causes mod_timer() on an uninitialized timer_list, triggering debugobjects warnings and possible panic when panic_on_warn=1. Fix this by rejecting revision 0 rule insertion when an existing timer with the same label is of ALARM type.
Quoted source text, attributed separately from HOL analysis.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=68983a354a655c35d3fb204489d383a2a051fda7 <32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44 || >=68983a354a655c35d3fb204489d383a2a051fda7 <144f88054ba0180467356f40895bd660b5dceeec || >=68983a354a655c35d3fb204489d383a2a051fda7 <28c7cfaf0c0ab17cbd7754092116fd1af45271f9 || >=68983a354a655c35d3fb204489d383a2a051fda7 <54080355999381fed4a26129579a5765bab87491 || >=68983a354a655c35d3fb204489d383a2a051fda7 <5e7ece24c5cb75a60402aad4d803c7898ea40aa9 || >=68983a354a655c35d3fb204489d383a2a051fda7 <f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1 || >=68983a354a655c35d3fb204489d383a2a051fda7 <f228b9ae2a7e84d1153616d8e71c4236cb1f1309 || >=68983a354a655c35d3fb204489d383a2a051fda7 <329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf | 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44, 144f88054ba0180467356f40895bd660b5dceeec, 28c7cfaf0c0ab17cbd7754092116fd1af45271f9, 54080355999381fed4a26129579a5765bab87491, 5e7ece24c5cb75a60402aad4d803c7898ea40aa9, f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1, f228b9ae2a7e84d1153616d8e71c4236cb1f1309, 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf |
| Linux/Linuxgeneric | 5.7 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Mar 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels IDLETIMER revision 0 rules reuse existing timers by label and always call mod_timer() on timer->timer. If the label was created first by revision 1 with XT_IDLETIMER_ALARM, the object uses alarm timer semantics and timer->timer is never initialized. Reusing that object from revision 0 causes mod_timer() on an uninitialized timer_list, triggering debugobjects warnings and possible panic when panic_on_warn=1. Fix this by rejecting revision 0 rule insertion when an existing timer with the same label is of ALARM type.
Quoted source text, attributed separately from HOL analysis.