{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-80634",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-26T14:34:25.777Z",
        "datePublished": "2026-08-28T06:48:49.022Z",
        "dateUpdated": "2026-08-28T06:48:49.022Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-28T06:48:49.022Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: flowtable: avoid num_encaps underflow on bridge VLAN untag\n\nThe DEV_PATH_BR_VLAN_UNTAG case post-decrements info->num_encaps\ninside WARN_ON_ONCE(). num_encaps is u8, so if it's already 0 the\ndecrement still happens and wraps it to 255. The break only leaves\nthe inner switch -- a later path entry can set info->indev back to\na real device, and we end up returning with num_encaps == 255.\n\nnft_dev_forward_path() then walks info.encap[] (size 2) up to\nnum_encaps, which means an OOB stack read and a bogus count copied\ninto the route descriptor.\n\nShould only happen on a malformed bridge path stack, hence the WARN,\nbut worth handling sanely. Move the decrement out of the WARN.\n\n[ While at this, remove the WARN_ON_ONCE since this can only happen\n  with a buggy bridge path stack --pablo ]."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/netfilter/nf_flow_table_path.c"
                    ],
                    "versions": [
                        {
                            "version": "e990cef6516daa4e1e236433579e333f74fd38cb",
                            "lessThan": "2f55fa28011c97d6495d5787808db10a8c2d690d",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "e990cef6516daa4e1e236433579e333f74fd38cb",
                            "lessThan": "e052f920773b73be49eb4d8702a9f85de7464363",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/netfilter/nf_flow_table_path.c"
                    ],
                    "versions": [
                        {
                            "version": "5.13",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.13",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.5",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.13",
                                    "versionEndExcluding": "7.1.5"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.13",
                                    "versionEndExcluding": "7.2"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/2f55fa28011c97d6495d5787808db10a8c2d690d"
                },
                {
                    "url": "https://git.kernel.org/stable/c/e052f920773b73be49eb4d8702a9f85de7464363"
                }
            ],
            "title": "netfilter: flowtable: avoid num_encaps underflow on bridge VLAN untag",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}