Answer in brief
CVE-2026-43057 records a High severity (CVSS 7.5) vulnerability in net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback. 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-2026-43057 records a High severity (CVSS 7.5) vulnerability in net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback. 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 7.5. 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 | >=a0478d7e888028f85fa7785ea838ce0ca09398e2 <2094a7cf91b71367b649f991aacc7b579f793d0b || >=2156d9e9f2e483c8c3906c0ea57ea312c1424235 <ed71cf465c75f5688b07a35d373cd1d6b589c8ea || >=041e2f945f82fdbd6fff577b79c33469430297aa <33670f780e0120c3dacda188c512bbffe0b6044c || >=864e3396976ef41de6cc7bc366276bf4e084fff2 <a98b78116a27e2a57b696b569b2cb431c95cf9b6 || >=864e3396976ef41de6cc7bc366276bf4e084fff2 <732fdeb2987c94b439d51f5cb9addddc2fc48c42 || >=864e3396976ef41de6cc7bc366276bf4e084fff2 <c4336a07eb6b2526dc2b62928b5104b41a7f81f5 || 794ddbb7b63b6828c75967b9bcd43b086716e7a1 || >=6.1.149 <6.1.168 || >=6.6.103 <6.6.134 || >=6.12.44 <6.12.81 || >=6.16.4 <6.17 | 2094a7cf91b71367b649f991aacc7b579f793d0b, ed71cf465c75f5688b07a35d373cd1d6b589c8ea, 33670f780e0120c3dacda188c512bbffe0b6044c, a98b78116a27e2a57b696b569b2cb431c95cf9b6, 732fdeb2987c94b439d51f5cb9addddc2fc48c42, c4336a07eb6b2526dc2b62928b5104b41a7f81f5, 6.1.168, 6.6.134, 6.12.81, 6.17 |
| Linux/Linuxgeneric | 6.17 | 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 1, 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: net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback NETIF_F_IPV6_CSUM only advertises support for checksum offload of packets without IPv6 extension headers. Packets with extension headers must fall back onto software checksumming. Since TSO depends on checksum offload, those must revert to GSO. The below commit introduces that fallback. It always checks network header length. For tunneled packets, the inner header length must be checked instead. Extend the check accordingly. A special case is tunneled packets without inner IP protocol. Such as RFC 6951 SCTP in UDP. Those are not standard IPv6 followed by transport header either, so also must revert to the software GSO path.
Quoted source text, attributed separately from HOL analysis.
CVSS is 7.5. 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 | >=a0478d7e888028f85fa7785ea838ce0ca09398e2 <2094a7cf91b71367b649f991aacc7b579f793d0b || >=2156d9e9f2e483c8c3906c0ea57ea312c1424235 <ed71cf465c75f5688b07a35d373cd1d6b589c8ea || >=041e2f945f82fdbd6fff577b79c33469430297aa <33670f780e0120c3dacda188c512bbffe0b6044c || >=864e3396976ef41de6cc7bc366276bf4e084fff2 <a98b78116a27e2a57b696b569b2cb431c95cf9b6 || >=864e3396976ef41de6cc7bc366276bf4e084fff2 <732fdeb2987c94b439d51f5cb9addddc2fc48c42 || >=864e3396976ef41de6cc7bc366276bf4e084fff2 <c4336a07eb6b2526dc2b62928b5104b41a7f81f5 || 794ddbb7b63b6828c75967b9bcd43b086716e7a1 || >=6.1.149 <6.1.168 || >=6.6.103 <6.6.134 || >=6.12.44 <6.12.81 || >=6.16.4 <6.17 | 2094a7cf91b71367b649f991aacc7b579f793d0b, ed71cf465c75f5688b07a35d373cd1d6b589c8ea, 33670f780e0120c3dacda188c512bbffe0b6044c, a98b78116a27e2a57b696b569b2cb431c95cf9b6, 732fdeb2987c94b439d51f5cb9addddc2fc48c42, c4336a07eb6b2526dc2b62928b5104b41a7f81f5, 6.1.168, 6.6.134, 6.12.81, 6.17 |
| Linux/Linuxgeneric | 6.17 | 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 1, 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: net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback NETIF_F_IPV6_CSUM only advertises support for checksum offload of packets without IPv6 extension headers. Packets with extension headers must fall back onto software checksumming. Since TSO depends on checksum offload, those must revert to GSO. The below commit introduces that fallback. It always checks network header length. For tunneled packets, the inner header length must be checked instead. Extend the check accordingly. A special case is tunneled packets without inner IP protocol. Such as RFC 6951 SCTP in UDP. Those are not standard IPv6 followed by transport header either, so also must revert to the software GSO path.
Quoted source text, attributed separately from HOL analysis.