{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89555", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.724Z", "datePublished": "2026-09-11T19:44:28.331Z", "dateUpdated": "2026-09-11T19:44:28.331Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-11T19:44:28.331Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmpls: reload header after pskb_may_pull()\n\nmpls_select_multipath() calls mpls_multipath_hash() to choose a nexthop\nwhen an MPLS route has multiple nexthops. While walking the MPLS label\nstack, the hash routine caches hdr for the current label. After finding\nthe bottom-of-stack label, it calls pskb_may_pull() before reading the\ninner IP header.\n\nIf an skb is constructed with the inner IP header in nonlinear data and\ninsufficient tailroom in the linear head, pskb_may_pull() calls\npskb_expand_head() to replace the skb head and free the old one. This\nleaves hdr pointing to freed memory. The IPv6 path can invalidate hdr\nagain when it performs a second pull for the larger header.\n\nThe issue was found through static analysis. A reproducer sending a legal\nGeneve packet through a bareudp/MPLS multipath setup triggered the same\nKASAN report in 2 of 2 unpatched runs:\n\n BUG: KASAN: slab-use-after-free in mpls_select_multipath\n Read of size 1 at addr ffff88800ecc6e20 by task ksoftirqd/1/23\n\n Call Trace:\n mpls_select_multipath\n mpls_forward\n __netif_receive_skb_list_core\n netif_receive_skb_list_internal\n napi_complete_done\n gro_cell_poll\n __napi_poll\n net_rx_action\n\n Freed by task 23:\n kfree\n pskb_expand_head\n __pskb_pull_tail\n mpls_select_multipath\n\nReload hdr from the current skb head after each successful pull before\nderiving the inner IPv4 or IPv6 header pointer."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/mpls/af_mpls.c"], "versions": [{"version": "9f427a0e474a67b454420c131709600d44850486", "lessThan": "fed638a248116b8a249bd4202d28e5934bdc65ad", "status": "affected", "versionType": "git"}, {"version": "9f427a0e474a67b454420c131709600d44850486", "lessThan": "d82b90a38c2ca8a0694428eab0e9551c23f2447d", "status": "affected", "versionType": "git"}, {"version": "9f427a0e474a67b454420c131709600d44850486", "lessThan": "49d38c1b4390412f8950d33dfaee0ccbd17beb81", "status": "affected", "versionType": "git"}, {"version": "9f427a0e474a67b454420c131709600d44850486", "lessThan": "29e63b8d9fc150cc191b1c6eb7e16e1247e1b650", "status": "affected", "versionType": "git"}, {"version": "ad864d9fce0ec56cc8f6afe5c6a0e6d7f484b9eb", "status": "affected", "versionType": "git"}, {"version": "4.9.8", "lessThan": "4.10", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/mpls/af_mpls.c"], "versions": [{"version": "4.10", "status": "affected"}, {"version": "0", "lessThan": "4.10", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3-rc1", "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": "4.10", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "7.3-rc1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.8"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/fed638a248116b8a249bd4202d28e5934bdc65ad"}, {"url": "https://git.kernel.org/stable/c/d82b90a38c2ca8a0694428eab0e9551c23f2447d"}, {"url": "https://git.kernel.org/stable/c/49d38c1b4390412f8950d33dfaee0ccbd17beb81"}, {"url": "https://git.kernel.org/stable/c/29e63b8d9fc150cc191b1c6eb7e16e1247e1b650"}], "title": "mpls: reload header after pskb_may_pull()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/mpls/af_mpls.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "fed638a248116b8a249bd4202d28e5934bdc65ad", "status": "affected", "version": "9f427a0e474a67b454420c131709600d44850486", "versionType": "git"}, {"lessThan": "d82b90a38c2ca8a0694428eab0e9551c23f2447d", "status": "affected", "version": "9f427a0e474a67b454420c131709600d44850486", "versionType": "git"}, {"lessThan": "49d38c1b4390412f8950d33dfaee0ccbd17beb81", "status": "affected", "version": "9f427a0e474a67b454420c131709600d44850486", "versionType": "git"}, {"lessThan": "29e63b8d9fc150cc191b1c6eb7e16e1247e1b650", "status": "affected", "version": "9f427a0e474a67b454420c131709600d44850486", "versionType": "git"}, {"status": "affected", "version": "ad864d9fce0ec56cc8f6afe5c6a0e6d7f484b9eb", "versionType": "git"}, {"lessThan": "4.10", "status": "affected", "version": "4.9.8", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/mpls/af_mpls.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.10"}, {"lessThan": "4.10", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3-rc1", "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\nmpls: reload header after pskb_may_pull()\n\nmpls_select_multipath() calls mpls_multipath_hash() to choose a nexthop\nwhen an MPLS route has multiple nexthops. While walking the MPLS label\nstack, the hash routine caches hdr for the current label. After finding\nthe bottom-of-stack label, it calls pskb_may_pull() before reading the\ninner IP header.\n\nIf an skb is constructed with the inner IP header in nonlinear data and\ninsufficient tailroom in the linear head, pskb_may_pull() calls\npskb_expand_head() to replace the skb head and free the old one. This\nleaves hdr pointing to freed memory. The IPv6 path can invalidate hdr\nagain when it performs a second pull for the larger header.\n\nThe issue was found through static analysis. A reproducer sending a legal\nGeneve packet through a bareudp/MPLS multipath setup triggered the same\nKASAN report in 2 of 2 unpatched runs:\n\n BUG: KASAN: slab-use-after-free in mpls_select_multipath\n Read of size 1 at addr ffff88800ecc6e20 by task ksoftirqd/1/23\n\n Call Trace:\n mpls_select_multipath\n mpls_forward\n __netif_receive_skb_list_core\n netif_receive_skb_list_internal\n napi_complete_done\n gro_cell_poll\n __napi_poll\n net_rx_action\n\n Freed by task 23:\n kfree\n pskb_expand_head\n __pskb_pull_tail\n mpls_select_multipath\n\nReload hdr from the current skb head after each successful pull before\nderiving the inner IPv4 or IPv6 header pointer."}], "id": "CVE-2026-89555", "lastModified": "2026-09-11T20:19:39.147", "metrics": {}, "published": "2026-09-11T20:19:39.147", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/29e63b8d9fc150cc191b1c6eb7e16e1247e1b650"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/49d38c1b4390412f8950d33dfaee0ccbd17beb81"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d82b90a38c2ca8a0694428eab0e9551c23f2447d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fed638a248116b8a249bd4202d28e5934bdc65ad"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: MPLS use-after-free vulnerability causes denial of service.", "id": "2532032", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532032"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["A flaw was found in the Linux kernel's Multiprotocol Label Switching (MPLS) subsystem. When processing specially crafted Geneve packets through an MPLS multipath setup, a use-after-free vulnerability occurs. This issue arises because a cached header pointer (`hdr`) is not reloaded after `pskb_may_pull()` potentially reallocates the packet buffer, leading to `hdr` pointing to freed memory. A remote attacker could exploit this to trigger a kernel crash, resulting in a denial of service."], "name": "CVE-2026-89555", "package_state": [{"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-11T19:44:28Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89555\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89555\nhttps://git.kernel.org/stable/c/29e63b8d9fc150cc191b1c6eb7e16e1247e1b650\nhttps://git.kernel.org/stable/c/49d38c1b4390412f8950d33dfaee0ccbd17beb81\nhttps://git.kernel.org/stable/c/d82b90a38c2ca8a0694428eab0e9551c23f2447d\nhttps://git.kernel.org/stable/c/fed638a248116b8a249bd4202d28e5934bdc65ad"], "threat_severity": "Moderate"}

{}