What’s Vulnerable › Vulnerabilities

CVE-2025-21789: LoongArch: csum: Fix OoB access in IP checksum code for negative lengths

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-02-27 · updated 2026-07-30
• Weakness: CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: LoongArch: csum: Fix OoB access in IP checksum code for negative lengths Commit 69e3a6aa6be2 ("LoongArch: Add checksum optimization for 64-bit system") would cause an undefined shift and an out-of-bounds read. Commit 8bd795fedb84 ("arm64: csum: Fix OoB access in IP checksum code for negative lengths") fixes the same issue on ARM64.

Affected products

• Linux kernel: from 6.4 before 6.6.79; from 6.7 before 6.12.16; from 6.13 before 6.13.4; 6.14-rc1, 6.14-rc2 — fixed in 6.12.16, 6.13.4, 6.6.79

How to fix

Upgrade to a fixed version: Linux kernel 6.12.16, 6.13.4, 6.6.79. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/6287f1a8c16138c2ec750953e35039634018c84a
• https://git.kernel.org/stable/c/964a8895704a22efc06a2a3276b624a5ae985a06
• https://git.kernel.org/stable/c/9f15a8df542c0f08732a67d1a14ee7c22948fb97
• https://git.kernel.org/stable/c/d6508ffff32b44b6d0de06704034e4eef1c307a7

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