Medium [CVE-2026-74473] use pskb_network_may_pull in route_shortcircuit
This medium-severity Red Hat Linux advisory covers CVE-2026-74473 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat package: kernel-rt.
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Summary
In the Linux kernel, the following vulnerability has been resolved: vxlan: use pskb_network_may_pull() in route_shortcircuit() route_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr)) (or ipv6hdr), which checks if bytes are available starting from skb->data.
However, in vxlan_xmit(), skb->data points to the MAC header, so skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20) only checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of IP header), leaving the rest of the IP header potentially un-pulled in non-linear frags.
Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled linear buffer length. Fix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to the length check to ensure the full network header is present in the linear buffer.
A flaw was found in the Linux kernel's Virtual Extensible LAN (VXLAN) implementation. An incorrect buffer length check in the `route_shortcircuit()` function, specifically when using `pskb_may_pull()`, can lead to reading beyond the allocated buffer length.
This occurs when processing IP headers in non-linear network packet fragments. This vulnerability could potentially allow an attacker to access sensitive information or cause a denial of service.
Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 1 hour ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 1 hour ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 1 hour ago·verify at source
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