{"id":"CVE-2026-53269","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: synproxy: add mutex to guard hook reference counting\n\nAs the synproxy infrastructure register netfilter hooks on-demand when a\nuser adds the first iptables t…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: synproxy: add mutex to guard hook reference counting\n\nAs the synproxy infrastructure register netfilter hooks on-demand when a\nuser adds the first iptables t…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.3, < 5.10.259","linux_kernel >= 5.11, < 5.15.210","linux_kernel >= 5.16, < 6.1.176","linux_kernel >= 6.2, < 6.6.143","linux_kernel >= 6.7, < 6.12.94","linux_kernel >= 6.13, < 6.18.36","linux_kernel >= 6.19, < 7.0.13","linux_kernel = 7.1"],"patched":["linux_kernel 7.0.13"],"published":"2026-06-25","updated":"2026-09-08","sourceUpdated":"2026-09-08T09:18:15.570","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53269","references":[{"url":"https://git.kernel.org/stable/c/0ec9ddc1bda261a2c57636c74c8b4e53000102c9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/0f8ba5e4c53d2e4a536aa68140beda9fe59b2f88","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2fcba19caaeb2a33017459d3430f057967bb91b6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/56ffbe3a08c01dcdb0d6adee9ce1e535bfb3b389","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/640441348258220e78daed40528b85b8afcedab6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/aaf80701dc2f7a48fe543961e21f8ca3924d587c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/debc57b83d5b323df74bf010c8d50fe26ad2ed6b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fbf0591275f50eae5733c3d7a8cd6c1e79933ffa","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00117,"epssPercentile":0.01876,"ingestedAt":"2026-09-08T15:33:26.945Z","slug":"CVE-2026-53269","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: synproxy: add mutex to guard hook reference counting\n\nAs the synproxy infrastructure register netfilter hooks on-demand when a\nuser adds the first iptables target or nftables expression, if done\nconcurrently they can race each other.\n\nIntroduce a mutex to serialize the refcount control blocks access from\nboth frontends. While a per namespace mutex might be more efficient, it\nis not needed for target/expression like SYNPROXY.\n\n## Affected\n\n- `linux_kernel >= 5.3, < 5.10.259`\n- `linux_kernel >= 5.11, < 5.15.210`\n- `linux_kernel >= 5.16, < 6.1.176`\n- `linux_kernel >= 6.2, < 6.6.143`\n- `linux_kernel >= 6.7, < 6.12.94`\n- `linux_kernel >= 6.13, < 6.18.36`\n- `linux_kernel >= 6.19, < 7.0.13`\n- `linux_kernel = 7.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.13`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}