CVE Catalog

CVE-2026-80901

Low risk· EPSS 6%
Published: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.16%

6th percentile - higher than 6% of all known CVEs

Summary

In the Linux kernel, IPVS lacks checksum validation for ICMPv6 packets from clients and for ICMPv6 responses from real servers (missing pseudo-header calculation). The fix introduces a helper ip_vs_checksum_common_check() and uses nf_checksum() for validating ICMP, TCP, and UDP, with correct IP offset for debugging. Checksum validation is performed only on LOCAL_IN, not on LOCAL_OUT or FORWARD.

Risk Assessment

Missing checksum validation could allow packet injection or modification in IPVS traffic, potentially leading to data integrity violations or man-in-the-middle attacks.

Recommendation

Apply the Linux kernel update containing this fix to ensure proper checksum validation in IPVS.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ipvs: fix the checksum validations ip_vs_in_icmp_v6() is missing checksum validation for ICMPv6 packets from clients. In fact, as for TCP/UDP we should validate the checksum for ICMP packets only when we mangle the packets on MASQ or on reply for tunnel. Also, Sashiko points out that handle_response_icmp() being common for IPv4 and IPv6 is missing the pseudo-header calculation while validating ICMPv6 messages from real servers which is a problem if checksum is not validated by the hardware. Fix the problems by creating ip_vs_checksum_common_check() helper and use it for TCP/UDP/ICMP both for IPv4 and IPv6. Rely on the nf_checksum() for validating the ICMP messages but use it also for TCP and UDP. Use correct IP offset for IP_VS_DBG_RL_PKT for TCP/UDP/SCTP. IPVS packets (TCP/UDP/SCTP/ICMP) do not need checksum validation on LOCAL_OUT (local clients or local real servers) and on FORWARD (traffic from servers on LAN). Do it only on LOCAL_IN, in case nf_checksum() is not called on PRE_ROUTING. Also, ip_vs_checksum_complete() can be marked static.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS