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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.3 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
- EPSS
- 0.17% probability · 6th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/2cf10d042562283ff4ae97c02d0993d4f1b5ea29
- https://git.kernel.org/stable/c/3adea1b1c04b57e08a5c12a1f42483760581ce61
- https://git.kernel.org/stable/c/b6cec6187b8632423cd99a94fd5e5ba165fa2a33
- https://git.kernel.org/stable/c/c39087ad0b97fc11a3b058dfc8db9fd370762cb9
- https://git.kernel.org/stable/c/dc9ffa1905e72f026d080880a2e4cfc42aa91000
- https://git.kernel.org/stable/c/e17a42199824973cd8212e95b21ffadf4114a21b
- https://git.kernel.org/stable/c/f21fa533a3ed15ada74106aac4b9ddd078fc6b7a
- https://git.kernel.org/stable/c/f5089008f90c0a7c5520dff3934e0af00adf322d
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.