{"apiVersion":"1.0","identifier":"CVE-2026-80634","description":"In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: avoid num_encaps underflow on bridge VLAN untag The DEV_PATH_BR_VLAN_UNTAG case post-decrements info->num_encaps inside WARN_ON_ONCE(). num_encaps is u8, so if it-s already 0 the decrement still happens and wraps it to 255. The break only leaves the inner switch -- a later path entry can set info->indev back to a real device, and we end up returning with num_encaps == 255. nft_dev_forward_path() then walks info.encap[] (size 2) up to num_encaps, which means an OOB stack read and a bogus count copied into the route descriptor. Should only happen on a malformed bridge path stack, hence the WARN, but worth handling sanely. Move the decrement out of the WARN. [ While at this, remove the WARN_ON_ONCE since this can only happen with a buggy bridge path stack --pablo ].","publishedAt":"2026-08-28T08:16:48","lastModifiedAt":"2026-08-28T08:16:48","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-80634","cvssScore":null,"cvssVector":"Pending","epssProbability":0.00155,"riskScore":0,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-80634","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-80634","en":"https://www.redsauce.net/en/cves/CVE-2026-80634","fr":"https://www.redsauce.net/fr/cves/CVE-2026-80634","pt":"https://www.redsauce.net/pt/cves/CVE-2026-80634","de":"https://www.redsauce.net/de/cves/CVE-2026-80634","sk":"https://www.redsauce.net/sk/cves/CVE-2026-80634","el":"https://www.redsauce.net/el/cves/CVE-2026-80634"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-80634"}}