{"id":"CVE-2026-89487","title":"openvswitch: only skb_tx_error() a packet we are about to drop","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nopenvswitch: only skb_tx_error() a packet we are about to drop\n\nqueue_userspace_packet() borrows the packet skb -- it only copies it into\na private netlink message (use…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-367"],"vendor":"Linux","product":"Linux","affected":["Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 5de5d554141a15b3f1f5c978fd9f7f4fd6d0600a","Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 48db11e115d1b232edc5591604adc6eda95cd545","Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 4477222e2916a18e273edc139c955ade6bbb7a69","Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 4d5c460ef8754be1d43b16dbf02695b008b207d6","Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 6767d70cf46f65807a6a4c4406a518e6c12e36ae","Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < e41a59fc056f63a7a1f42788913c53cc48d744aa","Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 5d85eef222cfd28e73deed7402c100229e8b9e6e","Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 0dbc2398fca3bb33eda963849f865ddb1b3aa05e","Linux c5f0c0e7525443add533495e93ba8de6feab2396","Linux 1674b4bf3eea3cac51b70778e89f8025f7cfe695","Linux >= 3.10.51 < 3.11","Linux >= 3.12.40 < 3.13","Linux 3.14"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:22:44.373891Z"},"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:47:37.837Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89487","references":[{"url":"https://git.kernel.org/stable/c/5de5d554141a15b3f1f5c978fd9f7f4fd6d0600a"},{"url":"https://git.kernel.org/stable/c/48db11e115d1b232edc5591604adc6eda95cd545"},{"url":"https://git.kernel.org/stable/c/4477222e2916a18e273edc139c955ade6bbb7a69"},{"url":"https://git.kernel.org/stable/c/4d5c460ef8754be1d43b16dbf02695b008b207d6"},{"url":"https://git.kernel.org/stable/c/6767d70cf46f65807a6a4c4406a518e6c12e36ae"},{"url":"https://git.kernel.org/stable/c/e41a59fc056f63a7a1f42788913c53cc48d744aa"},{"url":"https://git.kernel.org/stable/c/5d85eef222cfd28e73deed7402c100229e8b9e6e"},{"url":"https://git.kernel.org/stable/c/0dbc2398fca3bb33eda963849f865ddb1b3aa05e"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89487.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89487"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532517"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89487"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89487"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89487.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00129,"epssPercentile":0.02548,"scores":{"cna":7.8,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.452Z","slug":"CVE-2026-89487","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nopenvswitch: only skb_tx_error() a packet we are about to drop\n\nqueue_userspace_packet() borrows the packet skb -- it only copies it into\na private netlink message (user_skb) and does not own it; on return\ndo_execute_actions() keeps forwarding it through the flow's remaining\nactions. Its error path nevertheless calls skb_tx_error(skb), which via\nskb_zcopy_clear() does skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY,\nstripping SKBFL_SHARED_FRAG from that live skb (skb_tx_error()'s kerneldoc\nsays \"skb must be freed afterwards\").\n\nFor a MSG_ZEROCOPY skb carrying page-cache frags, SKBFL_SHARED_FRAG is\nwhat makes esp_input() skb_cow_data() before in-place AEAD; once it is\nstripped a later local ESP-in-UDP delivery decrypts in place over pages\nthe sender does not own -- an unprivileged page-cache write (the\n\"Fragnesia\" primitive).\ndo_execute_actions() ignores output_userspace()'s return value, so any\naction after a failed USERSPACE upcall inherits the stripped skb.\n\nMove the skb_tx_error() to the flow-miss drop path - the \"default\"\nbranch of ovs_dp_process_packet()'s switch(error), before kfree_skb().\n\nThe call has been here since commit 36d5fe6a0007 (\"core, nfqueue,\nopenvswitch: Orphan frags in skb_zerocopy and handle errors\") but was\nharmless until esp_input() began relying on SKBFL_SHARED_FRAG to gate\nin-place decrypt; only then did stripping it on a still-forwarded skb\nbecome a page-cache write primitive.\n\n## Affected\n\n- `Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 5de5d554141a15b3f1f5c978fd9f7f4fd6d0600a`\n- `Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 48db11e115d1b232edc5591604adc6eda95cd545`\n- `Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 4477222e2916a18e273edc139c955ade6bbb7a69`\n- `Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 4d5c460ef8754be1d43b16dbf02695b008b207d6`\n- `Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 6767d70cf46f65807a6a4c4406a518e6c12e36ae`\n- `Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < e41a59fc056f63a7a1f42788913c53cc48d744aa`\n- `Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 5d85eef222cfd28e73deed7402c100229e8b9e6e`\n- `Linux >= 36d5fe6a000790f56039afe26834265db0a3ad4c < 0dbc2398fca3bb33eda963849f865ddb1b3aa05e`\n- `Linux c5f0c0e7525443add533495e93ba8de6feab2396`\n- `Linux 1674b4bf3eea3cac51b70778e89f8025f7cfe695`\n- `Linux >= 3.10.51 < 3.11`\n- `Linux >= 3.12.40 < 3.13`\n- `Linux 3.14`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4, Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89487.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":223309,"id":"CVE-2026-89487","ts":1792180052493,"field":"cvss","old":"7","new":"7.8"},{"seq":203932,"id":"CVE-2026-89487","ts":1789490227640,"field":"cvss","old":"7.8","new":"7"},{"seq":198010,"id":"CVE-2026-89487","ts":1789384321371,"field":"cvss","old":"7.1","new":"7.8"},{"seq":183521,"id":"CVE-2026-89487","ts":1789356675712,"field":"cvss","old":"7.8","new":"7.1"},{"seq":153272,"id":"CVE-2026-89487","ts":1789285349830,"field":"cvss","old":null,"new":"7.8"},{"seq":153271,"id":"CVE-2026-89487","ts":1789285349830,"field":"severity","old":"none","new":"high"},{"seq":147091,"id":"CVE-2026-89487","ts":1789270195128,"field":"cvss","old":null,"new":"7.1"},{"seq":147090,"id":"CVE-2026-89487","ts":1789270195128,"field":"severity","old":"none","new":"high"}]}