{"cve":"CVE-2026-74478","nvd":{"published":"2026-08-15T13:17:52.600","modified":"2026-08-19T17:21:04.947","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\num: vector: fix use-after-free in vector_mmsg_rx()\n\nWhen vector_mmsg_rx() discards a packet whose overlay header fails\nverify_header(), it frees the skb and continues the loop:\n\n\tif (header_check < 0) {\n\t\tdev_kfree_skb_irq(skb);\n\t\tvp->estats.rx_encaps_errors++;\n\t\tcontinue;\n\t}\n\nThe normal and short-packet paths fall through to the bottom of the\nloop body, which clears the consumed slot and advances the cursors:\n\n\t(*skbuff_vector) = NULL;\n\tmmsg_vector++;\n\tskbuff_vector++;\n\nThe verify_header() < 0 path skips that via continue, so the freed skb\nis left in skbuff_vector[] and the cursors do not advance. The next\niteration reads the same slot, gets the freed skb, and frees it again,\nproducing a refcount underflow / use-after-free in the RX path.\n\nDiscard the slot the same way the other paths do before continuing.\n\nOnly transports whose verify_header() can return negative are affected:\nGRE and L2TPv3 do so on a cookie/session-id mismatch (raw/tap do not),\nso any peer on such a transport can trigger it without authentication.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":[],"references":["https://git.kernel.org/stable/c/180ff4c81faf01ec4e06082c9daa7c40518ead89","https://git.kernel.org/stable/c/4b9601595e8b6b5d18878cac0aeabc687d241111","https://git.kernel.org/stable/c/67d58ab4f2ccf7145f3da07e025735a09c79de1b","https://git.kernel.org/stable/c/7dc9781e320d664c9bdd50003c9acfddf363d1e1","https://git.kernel.org/stable/c/804b681002ead233abf49a3efd681f5468a835f9"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:10.689564601+00:00"},"epss":{"cve":"CVE-2026-74478","score":0.00864,"percentile":0.58653,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}