{"apiVersion":"1.0","identifier":"CVE-2026-99041","description":"In the Linux kernel, the following vulnerability has been resolved: ip6_gre: remove obsolete ERSPAN PMTU update A tc tunnel_key action can attach a METADATA_IP_TUNNEL dst to an skb, and mirred can redirect it to a native ip6erspan device. The legacy PMTU update in ip6erspan_tunnel_xmit() treats that metadata dst as a route. Since it has no output device, dst_dev(dst)->mtu dereferences NULL. On v7.2 with KASAN, an initial UID/GID 65534 process with CapEff 0 used self-created user and network namespaces to trigger: KASAN: null-ptr-deref RIP: ip6erspan_tunnel_xmit+0x10fc/0x2cc0 Kernel panic - not syncing: Fatal exception in interrupt The update is obsolete. Commit fe1a4ca0a2b7 (-ip6_gre: process toobig in a better way-) changed IPv6 GRE Too Big handling to update the underlay route and removed the equivalent block from __gre6_xmit(). ip6_tnl_xmit() then propagates the underlay PMTU to the overlay route. Remove the stale ERSPAN copy and its now-unused dst variable. This eliminates the metadata-dst dereference and keeps ERSPAN aligned with IPv6 GRE PMTU handling.","publishedAt":"2026-10-23T13:17:27","lastModifiedAt":"2026-10-30T13:21:41","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-99041","cvssScore":null,"cvssVector":null,"epssProbability":0.00173,"riskScore":null,"affectedProduct":"Linux kernel","affectedVersions":"<7.2","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-99041","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-99041","en":"https://www.redsauce.net/en/cves/CVE-2026-99041","fr":"https://www.redsauce.net/fr/cves/CVE-2026-99041","pt":"https://www.redsauce.net/pt/cves/CVE-2026-99041","de":"https://www.redsauce.net/de/cves/CVE-2026-99041","sk":"https://www.redsauce.net/sk/cves/CVE-2026-99041","el":"https://www.redsauce.net/el/cves/CVE-2026-99041"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-99041"}}