Answer in brief
CVE-2026-31518 records a Medium severity (CVSS 5.5) vulnerability in esp: fix skb leak with espintcp and async crypto. 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-2026-31518 records a Medium severity (CVSS 5.5) vulnerability in esp: fix skb leak with espintcp and async crypto. 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 5.5. 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 | >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <aca3ad0c262f54a5b5c95dda80a48365997d1224 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <41aafca57de4a4c026701622bd4648f112a9edcd || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <4820847e036ff1035b01b69ad68dfc17e7028fe9 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <6a3ec6efbc4f90e0ccb2e71574f07351f19996f4 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <df6f995358dc1f3c42484f5cfe241d7bd3e1cd15 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <88d386243ed374ac969dabd3bbc1409a31d81818 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <6aa9841d917532d0f2d932d1ff2f3a94305aaf47 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <0c0eef8ccd2413b0a10eb6bbd3442333b1e64dd2 | aca3ad0c262f54a5b5c95dda80a48365997d1224, 41aafca57de4a4c026701622bd4648f112a9edcd, 4820847e036ff1035b01b69ad68dfc17e7028fe9, 6a3ec6efbc4f90e0ccb2e71574f07351f19996f4, df6f995358dc1f3c42484f5cfe241d7bd3e1cd15, 88d386243ed374ac969dabd3bbc1409a31d81818, 6aa9841d917532d0f2d932d1ff2f3a94305aaf47, 0c0eef8ccd2413b0a10eb6bbd3442333b1e64dd2 |
| 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
Apr 22, 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: esp: fix skb leak with espintcp and async crypto When the TX queue for espintcp is full, esp_output_tail_tcp will return an error and not free the skb, because with synchronous crypto, the common xfrm output code will drop the packet for us. With async crypto (esp_output_done), we need to drop the skb when esp_output_tail_tcp returns an error.
Quoted source text, attributed separately from HOL analysis.
CVSS is 5.5. 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 | >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <aca3ad0c262f54a5b5c95dda80a48365997d1224 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <41aafca57de4a4c026701622bd4648f112a9edcd || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <4820847e036ff1035b01b69ad68dfc17e7028fe9 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <6a3ec6efbc4f90e0ccb2e71574f07351f19996f4 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <df6f995358dc1f3c42484f5cfe241d7bd3e1cd15 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <88d386243ed374ac969dabd3bbc1409a31d81818 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <6aa9841d917532d0f2d932d1ff2f3a94305aaf47 || >=e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 <0c0eef8ccd2413b0a10eb6bbd3442333b1e64dd2 | aca3ad0c262f54a5b5c95dda80a48365997d1224, 41aafca57de4a4c026701622bd4648f112a9edcd, 4820847e036ff1035b01b69ad68dfc17e7028fe9, 6a3ec6efbc4f90e0ccb2e71574f07351f19996f4, df6f995358dc1f3c42484f5cfe241d7bd3e1cd15, 88d386243ed374ac969dabd3bbc1409a31d81818, 6aa9841d917532d0f2d932d1ff2f3a94305aaf47, 0c0eef8ccd2413b0a10eb6bbd3442333b1e64dd2 |
| 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
Apr 22, 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: esp: fix skb leak with espintcp and async crypto When the TX queue for espintcp is full, esp_output_tail_tcp will return an error and not free the skb, because with synchronous crypto, the common xfrm output code will drop the packet for us. With async crypto (esp_output_done), we need to drop the skb when esp_output_tail_tcp returns an error.
Quoted source text, attributed separately from HOL analysis.