cbcvebase.
CVE-2026-53250
published 2026-06-25

CVE-2026-53250: In the Linux kernel, the following vulnerability has been resolved: xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata() The TX metadata area…

PriorityP341high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.11%
1.6th percentile
In the Linux kernel, the following vulnerability has been resolved: xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata() The TX metadata area resides in the UMEM buffer which is memory-mapped and concurrently writable by userspace. In xsk_skb_metadata(), csum_start and csum_offset are read from shared memory for bounds validation, then read again for skb assignment. A malicious userspace application can race to overwrite these values between the two reads, bypassing the bounds check and causing out-of-bounds memory access during checksum computation in the transmit path. Fix this by reading csum_start and csum_offset into local variables once, then using the local copies for both validation and assignment. Note that other metadata fields (flags, launch_time) and the cached csum fields may be mutually inconsistent due to concurrent userspace writes, but this is benign: the only security-critical invariant is that each field's validated value is the same one used, which local caching guarantees.

Affected

13 ranges
VendorProductVersion rangeFixed in
linuxlinux
linuxlinux>= 48eb03dd26304c24f03bdbb9382e89c8564e71df < 0dfe05b938435892875e07771170051346412df90dfe05b938435892875e07771170051346412df9
linuxlinux>= 48eb03dd26304c24f03bdbb9382e89c8564e71df < bfdfd2706d5fb2cd496a1506e680daf979309c8bbfdfd2706d5fb2cd496a1506e680daf979309c8b
linuxlinux>= 48eb03dd26304c24f03bdbb9382e89c8564e71df < 22ba97ea9cc1f63a0d0244fae38057ed452b6ac722ba97ea9cc1f63a0d0244fae38057ed452b6ac7
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 6.19 < 7.0.137.0.13
linuxlinux_kernel>= 6.8 < 6.18.366.18.36

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vendor_redhat7.8HIGH
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