{"cve":"CVE-2025-21703","nvd":{"published":"2025-02-18T15:15:18.633","modified":"2026-10-15T02:17:28.087","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetem: Update sch->q.qlen before qdisc_tree_reduce_backlog()\n\nqdisc_tree_reduce_backlog() notifies parent qdisc only if child\nqdisc becomes empty, therefore we need to reduce the backlog of the\nchild qdisc before calling it. Otherwise it would miss the opportunity\nto call cops->qlen_notify(), in the case of DRR, it resulted in UAF\nsince DRR uses ->qlen_notify() to maintain its active list.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/1f8e3f4a4b8b90ad274dfbc66fc7d55cb582f4d5","https://git.kernel.org/stable/c/6312555249082d6d8cc5321ff725df05482d8b83","https://git.kernel.org/stable/c/638ba5089324796c2ee49af10427459c2de35f71","https://git.kernel.org/stable/c/7b79ca9a1de6a428d486ff52fb3d602321c08f55","https://git.kernel.org/stable/c/7f31d74fcc556a9166b1bb20515542de7bb939d1"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:18.731010617+00:00"},"epss":{"cve":"CVE-2025-21703","score":0.00304,"percentile":0.22929,"date":"2026-10-26"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}