Answer in brief
CVE-2025-21766 records a Unknown severity vulnerability in ipv4: use RCU protection in __ip_rt_update_pmtu(). 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 1518F-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-2025-21766 records a Unknown severity vulnerability in ipv4: use RCU protection in __ip_rt_update_pmtu(). 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 1518F-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.
A CVSS score is not reported in the current record. 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 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <ce3c6165fce0f06305c806696882a3ad4b90e33f || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <ea07480b23225942208f1b754fea1e7ec486d37e || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <9b1766d1ff5fe496aabe9fc5f4e34e53f35c11c4 || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <4583748b65dee4d61bd50a2214715b4237bc152a || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <a39f61d212d822b3062d7f70fa0588e50e55664e || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <139512191bd06f1b496117c76372b2ce372c9a41 || f415c264176e6095e9dee823e09c5bdd0ee0d337 || 98776a365da509ad923083ae54b38ee521c52742 || 860e2cc78c697c95bc749abb20047239fa1722ea || 2b1be6c925cdf4638811765a9160796291494b89 || >=4.14.200 <4.15 || >=4.19.148 <4.20 || >=5.4.68 <5.5 || >=5.8.12 <5.9 | ce3c6165fce0f06305c806696882a3ad4b90e33f, ea07480b23225942208f1b754fea1e7ec486d37e, 9b1766d1ff5fe496aabe9fc5f4e34e53f35c11c4, 4583748b65dee4d61bd50a2214715b4237bc152a, a39f61d212d822b3062d7f70fa0588e50e55664e, 139512191bd06f1b496117c76372b2ce372c9a41, 4.15, 4.20, 5.5, 5.9 |
| Linux/Linuxgeneric | 5.9 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Feb 27, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: ipv4: use RCU protection in __ip_rt_update_pmtu() __ip_rt_update_pmtu() must use RCU protection to make sure the net structure it reads does not disappear.
Quoted source text, attributed separately from HOL analysis.
A CVSS score is not reported in the current record. 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 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <ce3c6165fce0f06305c806696882a3ad4b90e33f || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <ea07480b23225942208f1b754fea1e7ec486d37e || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <9b1766d1ff5fe496aabe9fc5f4e34e53f35c11c4 || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <4583748b65dee4d61bd50a2214715b4237bc152a || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <a39f61d212d822b3062d7f70fa0588e50e55664e || >=2fbc6e89b2f1403189e624cabaf73e189c5e50c6 <139512191bd06f1b496117c76372b2ce372c9a41 || f415c264176e6095e9dee823e09c5bdd0ee0d337 || 98776a365da509ad923083ae54b38ee521c52742 || 860e2cc78c697c95bc749abb20047239fa1722ea || 2b1be6c925cdf4638811765a9160796291494b89 || >=4.14.200 <4.15 || >=4.19.148 <4.20 || >=5.4.68 <5.5 || >=5.8.12 <5.9 | ce3c6165fce0f06305c806696882a3ad4b90e33f, ea07480b23225942208f1b754fea1e7ec486d37e, 9b1766d1ff5fe496aabe9fc5f4e34e53f35c11c4, 4583748b65dee4d61bd50a2214715b4237bc152a, a39f61d212d822b3062d7f70fa0588e50e55664e, 139512191bd06f1b496117c76372b2ce372c9a41, 4.15, 4.20, 5.5, 5.9 |
| Linux/Linuxgeneric | 5.9 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Feb 27, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: ipv4: use RCU protection in __ip_rt_update_pmtu() __ip_rt_update_pmtu() must use RCU protection to make sure the net structure it reads does not disappear.
Quoted source text, attributed separately from HOL analysis.