Vulnerability details
CVE-2026-23274
Linux LinuxSiemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFPSiemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPSiemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystemSiemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels
CVSS 3.1
7.8High
Official description
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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.8High | 3.1 | CVEProject cvelistV5 (CNA) (Linux) | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Linux | Linux | 5.7 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 68983a354a655c35d3fb204489d383a2a051fda7 ≤ v < 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 68983a354a655c35d3fb204489d383a2a051fda7 ≤ v < 28c7cfaf0c0ab17cbd7754092116fd1af45271f9 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 68983a354a655c35d3fb204489d383a2a051fda7 ≤ v < 54080355999381fed4a26129579a5765bab87491 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 68983a354a655c35d3fb204489d383a2a051fda7 ≤ v < 144f88054ba0180467356f40895bd660b5dceeec | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 68983a354a655c35d3fb204489d383a2a051fda7 ≤ v < f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 68983a354a655c35d3fb204489d383a2a051fda7 ≤ v < f228b9ae2a7e84d1153616d8e71c4236cb1f1309 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 68983a354a655c35d3fb204489d383a2a051fda7 ≤ v < 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 68983a354a655c35d3fb204489d383a2a051fda7 ≤ v < 5e7ece24c5cb75a60402aad4d803c7898ea40aa9 | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.5 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.5 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.6 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.6 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.7 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.7 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.5 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.5 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.6 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.6 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.7 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.7 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | All | CVEProject cvelistV5 (CNA) |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP | V3.1.5 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP | V3.1.6 ≤ v | CVEProject cvelistV5 (CNA) |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP | V3.1.7 ≤ v | CVEProject cvelistV5 (CNA) |
References and advisories
12- https://git.kernel.org/stable/c/32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44
- https://git.kernel.org/stable/c/144f88054ba0180467356f40895bd660b5dceeec
- https://git.kernel.org/stable/c/28c7cfaf0c0ab17cbd7754092116fd1af45271f9
- https://git.kernel.org/stable/c/54080355999381fed4a26129579a5765bab87491
- https://git.kernel.org/stable/c/5e7ece24c5cb75a60402aad4d803c7898ea40aa9
- https://git.kernel.org/stable/c/f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1
- https://git.kernel.org/stable/c/f228b9ae2a7e84d1153616d8e71c4236cb1f1309
- https://git.kernel.org/stable/c/329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
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Details
- Published
- 2026-03-20
- Last updated
- 2026-10-19
- State
- Published
- Assigner (CNA)
- Linux
Exploit prediction (EPSS)
0.18%
Probability of exploitation in 30 days
7.9%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-758Reliance on Undefined, Unspecified, or Implementation-Defined Behavior