{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-99041", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.387Z", "datePublished": "2026-10-23T12:22:00.403Z", "dateUpdated": "2026-10-23T12:22:00.403Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-23T12:22:00.403Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_gre: remove obsolete ERSPAN PMTU update\n\nA tc tunnel_key action can attach a METADATA_IP_TUNNEL dst to an skb,\nand mirred can redirect it to a native ip6erspan device. The legacy PMTU\nupdate in ip6erspan_tunnel_xmit() treats that metadata dst as a route.\nSince it has no output device, dst_dev(dst)->mtu dereferences NULL.\n\nOn v7.2 with KASAN, an initial UID/GID 65534 process with CapEff 0 used\nself-created user and network namespaces to trigger:\n\n KASAN: null-ptr-deref\n RIP: ip6erspan_tunnel_xmit+0x10fc/0x2cc0\n Kernel panic - not syncing: Fatal exception in interrupt\n\nThe update is obsolete. Commit fe1a4ca0a2b7 (\"ip6_gre: process toobig\nin a better way\") changed IPv6 GRE Too Big handling to update the\nunderlay route and removed the equivalent block from __gre6_xmit().\nip6_tnl_xmit() then propagates the underlay PMTU to the overlay route.\n\nRemove the stale ERSPAN copy and its now-unused dst variable. This\neliminates the metadata-dst dereference and keeps ERSPAN aligned with\nIPv6 GRE PMTU handling."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv6/ip6_gre.c"], "versions": [{"version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "lessThan": "b14a682ad7d45345701e08f9279d483a1da8b36c", "status": "affected", "versionType": "git"}, {"version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "lessThan": "f5b143f4cd3fb7673df8d727550478a4b762908a", "status": "affected", "versionType": "git"}, {"version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "lessThan": "2d06cb25a497d3a7034ef9d172626c2d6620a0f1", "status": "affected", "versionType": "git"}, {"version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "lessThan": "8f27260b989f488760289276377db24fbfb20bfa", "status": "affected", "versionType": "git"}, {"version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "lessThan": "8bc60db48e8cba35488bbd6e1f94aa990afa275a", "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/ipv6/ip6_gre.c"], "versions": [{"version": "4.16", "status": "affected"}, {"version": "0", "lessThan": "4.16", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.114", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.58", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.11", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "4.16", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.12.114"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.18.58"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "7.2.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b14a682ad7d45345701e08f9279d483a1da8b36c"}, {"url": "https://git.kernel.org/stable/c/f5b143f4cd3fb7673df8d727550478a4b762908a"}, {"url": "https://git.kernel.org/stable/c/2d06cb25a497d3a7034ef9d172626c2d6620a0f1"}, {"url": "https://git.kernel.org/stable/c/8f27260b989f488760289276377db24fbfb20bfa"}, {"url": "https://git.kernel.org/stable/c/8bc60db48e8cba35488bbd6e1f94aa990afa275a"}], "title": "ip6_gre: remove obsolete ERSPAN PMTU update", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/ipv6/ip6_gre.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "b14a682ad7d45345701e08f9279d483a1da8b36c", "status": "affected", "version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "versionType": "git"}, {"lessThan": "f5b143f4cd3fb7673df8d727550478a4b762908a", "status": "affected", "version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "versionType": "git"}, {"lessThan": "2d06cb25a497d3a7034ef9d172626c2d6620a0f1", "status": "affected", "version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "versionType": "git"}, {"lessThan": "8f27260b989f488760289276377db24fbfb20bfa", "status": "affected", "version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "versionType": "git"}, {"lessThan": "8bc60db48e8cba35488bbd6e1f94aa990afa275a", "status": "affected", "version": "5a963eb61b7c39e6c422b6e48619d19d04719358", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/ipv6/ip6_gre.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.16"}, {"lessThan": "4.16", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.114", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.58", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.11", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_gre: remove obsolete ERSPAN PMTU update\n\nA tc tunnel_key action can attach a METADATA_IP_TUNNEL dst to an skb,\nand mirred can redirect it to a native ip6erspan device. The legacy PMTU\nupdate in ip6erspan_tunnel_xmit() treats that metadata dst as a route.\nSince it has no output device, dst_dev(dst)->mtu dereferences NULL.\n\nOn v7.2 with KASAN, an initial UID/GID 65534 process with CapEff 0 used\nself-created user and network namespaces to trigger:\n\n KASAN: null-ptr-deref\n RIP: ip6erspan_tunnel_xmit+0x10fc/0x2cc0\n Kernel panic - not syncing: Fatal exception in interrupt\n\nThe update is obsolete. Commit fe1a4ca0a2b7 (\"ip6_gre: process toobig\nin a better way\") changed IPv6 GRE Too Big handling to update the\nunderlay route and removed the equivalent block from __gre6_xmit().\nip6_tnl_xmit() then propagates the underlay PMTU to the overlay route.\n\nRemove the stale ERSPAN copy and its now-unused dst variable. This\neliminates the metadata-dst dereference and keeps ERSPAN aligned with\nIPv6 GRE PMTU handling."}], "id": "CVE-2026-99041", "lastModified": "2026-10-23T13:17:27.487", "metrics": {}, "published": "2026-10-23T13:17:27.487", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2d06cb25a497d3a7034ef9d172626c2d6620a0f1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8bc60db48e8cba35488bbd6e1f94aa990afa275a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8f27260b989f488760289276377db24fbfb20bfa"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b14a682ad7d45345701e08f9279d483a1da8b36c"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f5b143f4cd3fb7673df8d727550478a4b762908a"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}