net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback (Linux Linux)

CVE-2026-43057
HIGH 7.5

At a glance

Source
NVD
EPSS
EPSS 0.44 % · percentile 38 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

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.

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HLinux
CVSS 3.1HIGH 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected a0478d7e888028f85fa7785ea838ce0ca09398e2 < 2094a7cf91b71367b649f991aacc7b579f793d0b ; affected 2156d9e9f2e483c8c3906c0ea57ea312c1424235 < ed71cf465c75f5688b07a35d373cd1d6b589c8ea ; affected 041e2f945f82fdbd6fff577b79c33469430297aa < 33670f780e0120c3dacda188c512bbffe0b6044c ; affected 864e3396976ef41de6cc7bc366276bf4e084fff2 < a98b78116a27e2a57b696b569b2cb431c95cf9b6 ; affected 864e3396976ef41de6cc7bc366276bf4e084fff2 < 732fdeb2987c94b439d51f5cb9addddc2fc48c42 ; affected 864e3396976ef41de6cc7bc366276bf4e084fff2 < c4336a07eb6b2526dc2b62928b5104b41a7f81f5
Linux · Linuxaffected 6.17 ; unaffected 0 < 6.17 ; unaffected 6.1.168 ≤ 6.1.* ; unaffected 6.6.134 ≤ 6.6.* ; unaffected 6.12.81 ≤ 6.12.* ; unaffected 6.18.22 ≤ 6.18.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD