CVE-2026-72019
In the Linux kernel, the following vulnerability has been resolved: macsec: don't read an unset MAC header in macsec_encrypt() macsec_encrypt() reads the Ethernet header via eth_hdr(skb) (skb->head + skb->mac_header) to memmove() the 12 source/destination MAC bytes forward and make room for the SecTAG. On the AF_PACKET SOCK_RAW + PACKET_QDISC_BYPASS transmit path the skb reaches the macsec ndo_start_xmit() with the MAC header unset, so eth_hdr(skb) resolves to skb->head + (u16)~0 and the read is out of bounds: a 12-byte heap over-read that is also emitted on the wire as the frame's outer source/destination MAC. KASAN reports a slab-out-of-bounds read in macsec_start_xmit() on 6.0; on current mainline a CONFIG_DEBUG_NET build flags it as an unset mac header in skb_mac_header(). On the TX path the L2 header is at skb->data, so use skb_eth_hdr(), added by commit 96cc4b69581d ("macvlan: do not assume mac_header is set in macvlan_broadcast()") for exactly this purpose.
Affected versions
Linux kernel versions
4.6
and later are affected. Fixed in
6.1.178,
6.6.145,
6.12.97,
6.18.40,
7.1.5,
7.2-rc3
and their respective stable series.
References
6 totalFrequently asked questions
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What is CVE-2026-72019?
CVE-2026-72019 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.6 onward and has been patched in 6.1.178, 6.6.145, 6.12.97 and others. CVE-2026-72019 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-72019?
Yes. CVE-2026-72019 has been patched. Fixed versions include 6.1.178, 6.6.145, 6.12.97 and others. If you are running Linux kernel 4.6 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-72019 actively exploited?
No. CVE-2026-72019 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.