{"id":"CVE-2025-21765","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: use RCU protection in ip6_default_advmss()\n\nip6_default_advmss() needs rcu protection to make\nsure the net structure it reads does not disappear.","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: use RCU protection in ip6_default_advmss()\n\nip6_default_advmss() needs rcu protection to make\nsure the net structure it reads does not disappear.","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 >= 2.6.26, < 5.4.291","linux_kernel >= 5.5, < 5.10.235","linux_kernel >= 5.11, < 5.15.179","linux_kernel >= 5.16, < 6.1.129","linux_kernel >= 6.2, < 6.6.79","linux_kernel >= 6.7, < 6.12.16","linux_kernel >= 6.13, < 6.13.4","linux_kernel = 6.14"],"patched":["linux_kernel 6.13.4"],"published":"2025-02-27","updated":"2026-07-14","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-21765","references":[{"url":"https://git.kernel.org/stable/c/28de355b63ad42309ed5a03ee7c436c90512265b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3c8ffcd248da34fc41e52a46e51505900115fc2a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4176a68b0db8fc74ac14fcd00ba8231371051dc2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/550ed693f47370502a71b85382e7f9e6417300b8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/713a40c892f40300d63691d9f85b2a23b48fe1e8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/78ad057472d8c76e0602402269222f9f9c698790","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/84212387caadb211cd9dadd6fd5563bd37dc1f5e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d02f30d220ef9511568a48dba8a9004c65f8d904","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-265688.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00613,"epssPercentile":0.47999,"ingestedAt":"2026-07-14T13:36:55.697Z","slug":"CVE-2025-21765","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nipv6: use RCU protection in ip6_default_advmss()\n\nip6_default_advmss() needs rcu protection to make\nsure the net structure it reads does not disappear.\n\n## Affected\n\n- `linux_kernel >= 2.6.26, < 5.4.291`\n- `linux_kernel >= 5.5, < 5.10.235`\n- `linux_kernel >= 5.11, < 5.15.179`\n- `linux_kernel >= 5.16, < 6.1.129`\n- `linux_kernel >= 6.2, < 6.6.79`\n- `linux_kernel >= 6.7, < 6.12.16`\n- `linux_kernel >= 6.13, < 6.13.4`\n- `linux_kernel = 6.14`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.13.4`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}