CVE-2026-43057
Published: May 1, 2026· Updated: May 6, 2026
Official Description
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.
Technical Analysis
CVE-2026-43057 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (6)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-43057 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts