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 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.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:*

History

08 Jul 2026, 13:04

Type Values Removed Values Added
CWE CWE-367
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:*
First Time Linux linux Kernel
Linux
References () https://git.kernel.org/stable/c/0dfe05b938435892875e07771170051346412df9 - () https://git.kernel.org/stable/c/0dfe05b938435892875e07771170051346412df9 - Patch
References () https://git.kernel.org/stable/c/22ba97ea9cc1f63a0d0244fae38057ed452b6ac7 - () https://git.kernel.org/stable/c/22ba97ea9cc1f63a0d0244fae38057ed452b6ac7 - Patch
References () https://git.kernel.org/stable/c/bfdfd2706d5fb2cd496a1506e680daf979309c8b - () https://git.kernel.org/stable/c/bfdfd2706d5fb2cd496a1506e680daf979309c8b - Patch

28 Jun 2026, 08:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8

25 Jun 2026, 09:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-06-25 09:16

Updated : 2026-07-08 13:04


NVD link : CVE-2026-53250

Mitre link : CVE-2026-53250

CVE.ORG link : CVE-2026-53250


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-367

Time-of-check Time-of-use (TOCTOU) Race Condition