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CVE-2025-21629

mediumCVSS 5.5covered by 1 sourcefirst seen 2026-08-06

CSIRTS triage

What
IPv6 checksum offload for BIG TCP packets was re-enabled to prevent denial of service.
Who is affected
Systems using IPv6 checksum offload with Big TCP packet handling.
Urgency
Moderately urgent as the issue can cause network availability problems.
Action
Apply the kernel patch that re-enables NETIF_F_IPV6_CSUM offload for BIG TCP packets.

AI-assisted analysis generated from the source advisory — verify against the original.

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Exploitation outlook

Advisory coverage (1)

External references

NVD record for CVE-2025-21629

CVE.org record

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