Description
In the Linux kernel, the following vulnerability has been resolved: gue: validate REMCSUM private option length GUE private flags can indicate that remote checksum offload metadata is present. The private flags field itself is accounted for by guehdr_flags_len(), but guehdr_priv_flags_len() currently returns 0 even when GUE_PFLAG_REMCSUM is set. This lets a packet with only the private flags field pass validate_gue_flags(), after which gue_remcsum() and gue_gro_remcsum() read the missing REMCSUM start/offset fields from the following bytes. Account for GUE_PLEN_REMCSUM when GUE_PFLAG_REMCSUM is present so that malformed packets are rejected during option validation.
References8
- git.kernel.org/stable/c/158b9995d3c87f3b93f5c22df54a12e12a3438b3
- git.kernel.org/stable/c/2a99224c120823987e4d829726f4ecb33e03fc1e
- git.kernel.org/stable/c/2c4de9988e9ddc760b750d6b6e701c35ff60ad14
- git.kernel.org/stable/c/4a4a1d41c6e901e773bcf795f562a47fa71f692a
- git.kernel.org/stable/c/61e78679c7c9ca685bff58e4b6348304dc60aafd
- git.kernel.org/stable/c/7c6876ec1b227261b51803f784c7be1b2242a1a0
- git.kernel.org/stable/c/d335dcc6f521571d57117b8deeebc940836e5450
- git.kernel.org/stable/c/f618cbe9b24cd0202004d2db781d5f80ab77037f
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 55 · as of 11 November 2026
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