Answer in brief
CVE-2026-23270 records a High severity (CVSS 7.8) vulnerability in net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks. 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 | >=172ba7d46c202e679f3ccb10264c67416aaeb1c4 <bc4e5bb529823a09f02dbe96169de679a9db26e0 || >=0b5b831122fc3789fff75be433ba3e4dd7b779d4 <fb3c380a54e33d1fd272cc342faa906d787d7ef1 || >=73f7da5fd124f2cda9161e2e46114915e6e82e97 <5a110ddcc99bda77a28598b3555fe009eaab3828 || >=3f14b377d01d8357eba032b4cabc8c1149b458b6 <524ce8b4ea8f64900b6c52b6a28df74f6bc0801e || >=3f14b377d01d8357eba032b4cabc8c1149b458b6 <380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6 || >=3f14b377d01d8357eba032b4cabc8c1149b458b6 <9deda0fcda5c1f388c5e279541850b71a2ccfcf4 || >=3f14b377d01d8357eba032b4cabc8c1149b458b6 <11cb63b0d1a0685e0831ae3c77223e002ef18189 || f5346df0591d10bc948761ca854b1fae6d2ef441 || >=5.15.148 <5.15.203 || >=6.1.75 <6.1.167 || >=6.6.14 <6.6.130 || >=6.7.2 <6.8 | bc4e5bb529823a09f02dbe96169de679a9db26e0, fb3c380a54e33d1fd272cc342faa906d787d7ef1, 5a110ddcc99bda77a28598b3555fe009eaab3828, 524ce8b4ea8f64900b6c52b6a28df74f6bc0801e, 380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6, 9deda0fcda5c1f388c5e279541850b71a2ccfcf4, 11cb63b0d1a0685e0831ae3c77223e002ef18189, 5.15.203, 6.1.167, 6.6.130, 6.8 |
| Linux/Linuxgeneric | 6.8 | 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 | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Mar 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 8, 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: net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks As Paolo said earlier [1]: "Since the blamed commit below, classify can return TC_ACT_CONSUMED while the current skb being held by the defragmentation engine. As reported by GangMin Kim, if such packet is that may cause a UaF when the defrag engine later on tries to tuch again such packet." act_ct was never meant to be used in the egress path, however some users are attaching it to egress today [2]. Attempting to reach a middle ground, we noticed that, while most qdiscs are not handling TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we address the issue by only allowing act_ct to bind to clsact/ingress qdiscs and shared blocks. That way it's still possible to attach act_ct to egress (albeit only with clsact). [1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/ [2] https://lore.kernel.org/netdev/[email protected]/
Quoted source text, attributed separately from HOL analysis.