Answer in brief
CVE-2026-43284 records a High severity (CVSS 8.8) vulnerability in xfrm: esp: avoid in-place decrypt on shared skb frags. 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-2026-43284 records a High severity (CVSS 8.8) vulnerability in xfrm: esp: avoid in-place decrypt on shared skb frags. 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 8.8. 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 | >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <a6cb440f274a22456ef3e86b457344f1678f38f9 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <ab8b995323e5237041472d07e5055f5f7dcdf15b || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <fe785bb3a8096dffcc4048a85cd0c83337eeecad || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <5d55c7336f8032d434adcc5fab987ccc93a44aec || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <8253aab4659ca16116b522203c2a6b18dccacea7 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <50ed1e7873100f77abad20fd31c51029bc49cd03 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <b54edf1e9a3fd3491bdcb82a21f8d21315271e0d || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <71a1d9d985d26716f74d21f18ee8cac821b06e97 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <52646cbd00e765a6db9c3afe9535f26218276034 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4 | a6cb440f274a22456ef3e86b457344f1678f38f9, ab8b995323e5237041472d07e5055f5f7dcdf15b, fe785bb3a8096dffcc4048a85cd0c83337eeecad, 5d55c7336f8032d434adcc5fab987ccc93a44aec, 8253aab4659ca16116b522203c2a6b18dccacea7, 50ed1e7873100f77abad20fd31c51029bc49cd03, b54edf1e9a3fd3491bdcb82a21f8d21315271e0d, 71a1d9d985d26716f74d21f18ee8cac821b06e97, 52646cbd00e765a6db9c3afe9535f26218276034, f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4 |
| Linux/Linuxgeneric | 4.11 | 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
May 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 1, 2026
In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change ESP output. In esp_output_head(), the path that appends the ESP trailer to existing skb tailroom without calling skb_cow_data() is not reachable for nonlinear skbs: skb_tailroom() returns zero when skb->data_len is nonzero, while ESP tailen is positive. Thus ESP output will either use the separate destination-frag path or fall back to skb_cow_data().
Quoted source text, attributed separately from HOL analysis.
CVSS is 8.8. 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 | >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <a6cb440f274a22456ef3e86b457344f1678f38f9 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <ab8b995323e5237041472d07e5055f5f7dcdf15b || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <fe785bb3a8096dffcc4048a85cd0c83337eeecad || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <5d55c7336f8032d434adcc5fab987ccc93a44aec || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <8253aab4659ca16116b522203c2a6b18dccacea7 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <50ed1e7873100f77abad20fd31c51029bc49cd03 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <b54edf1e9a3fd3491bdcb82a21f8d21315271e0d || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <71a1d9d985d26716f74d21f18ee8cac821b06e97 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <52646cbd00e765a6db9c3afe9535f26218276034 || >=cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4 | a6cb440f274a22456ef3e86b457344f1678f38f9, ab8b995323e5237041472d07e5055f5f7dcdf15b, fe785bb3a8096dffcc4048a85cd0c83337eeecad, 5d55c7336f8032d434adcc5fab987ccc93a44aec, 8253aab4659ca16116b522203c2a6b18dccacea7, 50ed1e7873100f77abad20fd31c51029bc49cd03, b54edf1e9a3fd3491bdcb82a21f8d21315271e0d, 71a1d9d985d26716f74d21f18ee8cac821b06e97, 52646cbd00e765a6db9c3afe9535f26218276034, f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4 |
| Linux/Linuxgeneric | 4.11 | 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
May 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 1, 2026
In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change ESP output. In esp_output_head(), the path that appends the ESP trailer to existing skb tailroom without calling skb_cow_data() is not reachable for nonlinear skbs: skb_tailroom() returns zero when skb->data_len is nonzero, while ESP tailen is positive. Thus ESP output will either use the separate destination-frag path or fall back to skb_cow_data().
Quoted source text, attributed separately from HOL analysis.