CVE Catalog

CVE-2026-89562

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

In the Linux kernel, ip6gre_tnl_link_config_route() incorrectly accumulates the lower device's hardware header length into dev->hard_header_len for NBMA ip6gre tunnels. This results in an incorrect hardware header length for the tunnel, potentially causing packet transmission issues.

Risk Assessment

Incorrect hardware header length can cause packet transmission errors over NBMA ip6gre tunnels, leading to connectivity loss or network malfunction.

Recommendation

Update the Linux kernel to a version containing the fix that keeps the lower device header in needed_headroom and sets hard_header_len only for ARPHRD_IP6GRE devices with header_ops.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ip6_gre: fix hardware header length for NBMA tunnels ip6gre_tnl_link_config_route() accumulates the lower device's hardware header length into dev->hard_header_len whenever header_ops is set. This is incorrect for both users of header_ops. ip6gretap and ip6erspan have a fixed Ethernet hardware header length. For an NBMA ip6gre tunnel, ip6gre_header() creates only the GRE header, the optional FOU or GUE header, and the outer IPv6 header. The lower device header is headroom needed later, not part of the tunnel device's hardware header. Keep the lower device header in needed_headroom. Set hard_header_len to the tunnel header length only for ARPHRD_IP6GRE devices with header_ops, and leave the fixed Ethernet header length unchanged for tap and erspan devices.

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