CVE-2026-74478

CVE CVE-2026-74478EUVD EUVD-2026-59671Published 2026-08-15T12:27:12.000ZLast changed 2026-08-19T16:37:30.000ZCVSS 9.8

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: um: vector: fix use-after-free in vector_mmsg_rx() When vector_mmsg_rx() discards a packet whose overlay header fails verify_header(), it frees the skb and continues the loop: if (header_check < 0) { dev_kfree_skb_irq(skb); vp->estats.rx_encaps_errors++; continue; } The normal and short-packet paths fall through to the bottom of the loop body, which clears the consumed slot and advances the cursors: (*skbuff_vector) = NULL; mmsg_vector++; skbuff_vector++; The verify_header() < 0 path skips that via continue, so the freed skb is left in skbuff_vector[] and the cursors do not advance. The next iteration reads the same slot, gets the freed skb, and frees it again, producing a refcount underflow / use-after-free in the RX path. Discard the slot the same way the other paths do before continuing. Only transports whose verify_header() can return negative are affected: GRE and L2TPv3 do so on a cookie/session-id mismatch (raw/tap do not), so any peer on such a transport can trigger it without authentication.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux 4.17; 49da7e64f33e80edffb1a9eeb230fa4c3f42dffb <967c779c9853d2a1cc9cd8e61d300250c348f3d9; patch: 5.10.265; patch: 5.15.216; patch: 7.1.8; 49da7e64f33e80edffb1a9eeb230fa4c3f42dffb <180ff4c81faf01ec4e06082c9daa7c40518ead89; patch: 6.12.103; patch: 6.1.183; 49da7e64f33e80edffb1a9eeb230fa4c3f42dffb <4b9601595e8b6b5d18878cac0aeabc687d241111; patch: 7.2; 49da7e64f33e80edffb1a9eeb230fa4c3f42dffb <804b681002ead233abf49a3efd681f5468a835f9; patch: 0; 49da7e64f33e80edffb1a9eeb230fa4c3f42dffb <a7bc015bb798c525e7a82dd14225c6aeb994274b; 49da7e64f33e80edffb1a9eeb230fa4c3f42dffb <7dc9781e320d664c9bdd50003c9acfddf363d1e1; 49da7e64f33e80edffb1a9eeb230fa4c3f42dffb <af421e9aed3920c7ac88c24daa48606c7112feca; patch: 6.18.44; patch: 6.6.151; 49da7e64f33e80edffb1a9eeb230fa4c3f42dffb <67d58ab4f2ccf7145f3da07e025735a09c79de1b

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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