Answer in brief
CVE-2026-23351 records a High severity (CVSS 7.8) vulnerability in netfilter: nft_set_pipapo: split gc into unlink and reclaim phase. 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-2026-23351 records a High severity (CVSS 7.8) vulnerability in netfilter: nft_set_pipapo: split gc into unlink and reclaim phase. 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 | >=3c4287f62044a90e73a561aa05fc46e62da173da <65ca51b9fb85477ab92a04295aed34b38f7c062e || >=3c4287f62044a90e73a561aa05fc46e62da173da <c0f1f85097ac2b6e7d750fe4d05807985cd3fd3a || >=3c4287f62044a90e73a561aa05fc46e62da173da <16f3595c0441d87dfa005c47d8f95be213afaa9e || >=3c4287f62044a90e73a561aa05fc46e62da173da <7864c667aed01a58b87ca518a631322cd0ac34c0 || >=3c4287f62044a90e73a561aa05fc46e62da173da <c12d570d71920903a1a0468b7d13b085203d0c93 || >=3c4287f62044a90e73a561aa05fc46e62da173da <500a50a301ce962b019ab95053ac70264fec2c21 || >=3c4287f62044a90e73a561aa05fc46e62da173da <aff13667708dfa0dce136b8efd81baa9fa6ef261 || >=3c4287f62044a90e73a561aa05fc46e62da173da <9df95785d3d8302f7c066050117b04cd3c2048c2 | 65ca51b9fb85477ab92a04295aed34b38f7c062e, c0f1f85097ac2b6e7d750fe4d05807985cd3fd3a, 16f3595c0441d87dfa005c47d8f95be213afaa9e, 7864c667aed01a58b87ca518a631322cd0ac34c0, c12d570d71920903a1a0468b7d13b085203d0c93, 500a50a301ce962b019ab95053ac70264fec2c21, aff13667708dfa0dce136b8efd81baa9fa6ef261, 9df95785d3d8302f7c066050117b04cd3c2048c2 |
| Linux/Linuxgeneric | 5.6 | 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 25, 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: nft_set_pipapo: split gc into unlink and reclaim phase Yiming Qian reports Use-after-free in the pipapo set type: Under a large number of expired elements, commit-time GC can run for a very long time in a non-preemptible context, triggering soft lockup warnings and RCU stall reports (local denial of service). We must split GC in an unlink and a reclaim phase. We cannot queue elements for freeing until pointers have been swapped. Expired elements are still exposed to both the packet path and userspace dumpers via the live copy of the data structure. call_rcu() does not protect us: dump operations or element lookups starting after call_rcu has fired can still observe the free'd element, unless the commit phase has made enough progress to swap the clone and live pointers before any new reader has picked up the old version. This a similar approach as done recently for the rbtree backend in commit 35f83a75529a ("netfilter: nft_set_rbtree: don't gc elements on insert").
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 | >=3c4287f62044a90e73a561aa05fc46e62da173da <65ca51b9fb85477ab92a04295aed34b38f7c062e || >=3c4287f62044a90e73a561aa05fc46e62da173da <c0f1f85097ac2b6e7d750fe4d05807985cd3fd3a || >=3c4287f62044a90e73a561aa05fc46e62da173da <16f3595c0441d87dfa005c47d8f95be213afaa9e || >=3c4287f62044a90e73a561aa05fc46e62da173da <7864c667aed01a58b87ca518a631322cd0ac34c0 || >=3c4287f62044a90e73a561aa05fc46e62da173da <c12d570d71920903a1a0468b7d13b085203d0c93 || >=3c4287f62044a90e73a561aa05fc46e62da173da <500a50a301ce962b019ab95053ac70264fec2c21 || >=3c4287f62044a90e73a561aa05fc46e62da173da <aff13667708dfa0dce136b8efd81baa9fa6ef261 || >=3c4287f62044a90e73a561aa05fc46e62da173da <9df95785d3d8302f7c066050117b04cd3c2048c2 | 65ca51b9fb85477ab92a04295aed34b38f7c062e, c0f1f85097ac2b6e7d750fe4d05807985cd3fd3a, 16f3595c0441d87dfa005c47d8f95be213afaa9e, 7864c667aed01a58b87ca518a631322cd0ac34c0, c12d570d71920903a1a0468b7d13b085203d0c93, 500a50a301ce962b019ab95053ac70264fec2c21, aff13667708dfa0dce136b8efd81baa9fa6ef261, 9df95785d3d8302f7c066050117b04cd3c2048c2 |
| Linux/Linuxgeneric | 5.6 | 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 25, 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: nft_set_pipapo: split gc into unlink and reclaim phase Yiming Qian reports Use-after-free in the pipapo set type: Under a large number of expired elements, commit-time GC can run for a very long time in a non-preemptible context, triggering soft lockup warnings and RCU stall reports (local denial of service). We must split GC in an unlink and a reclaim phase. We cannot queue elements for freeing until pointers have been swapped. Expired elements are still exposed to both the packet path and userspace dumpers via the live copy of the data structure. call_rcu() does not protect us: dump operations or element lookups starting after call_rcu has fired can still observe the free'd element, unless the commit phase has made enough progress to swap the clone and live pointers before any new reader has picked up the old version. This a similar approach as done recently for the rbtree backend in commit 35f83a75529a ("netfilter: nft_set_rbtree: don't gc elements on insert").
Quoted source text, attributed separately from HOL analysis.