Kernel memory corruption via deferred SFQ limit update
Published May 1, 2025 · Updated Aug 5, 2026
Out-of-bounds access in affected Linux kernel releases allows local users to corrupt kernel memory via crafted SFQ qdisc settings. sch_sfq validates limit before flows, depth, or divisor changes recompute it, permitting a zero effective limit whose decrement becomes index 65535 in sfq_link. An unprivileged local user can obtain CAP_NET_ADMIN in a user namespace and trigger repeatable kernel memory corruption, an oops, or a panic without interaction.
Summary
What happened
Out-of-bounds access in affected Linux kernel releases allows local users to corrupt kernel memory via crafted SFQ qdisc settings. sch_sfq validates limit before flows, depth, or divisor changes recompute it, permitting a zero effective limit whose decrement becomes index 65535 in sfq_link. An unprivileged local user can obtain CAP_NET_ADMIN in a user namespace and trigger repeatable kernel memory corruption, an oops, or a panic without interaction.
The record
- CVE
- CVE-2025-37752
- Published
- May 1, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 1, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10685681bafce6febb39770f3387621bf5d67d0b <b36a68192037d1614317a09b0d78c7814e2eecf9
- Affected versionversion=10685681bafce6febb39770f3387621bf5d67d0b <b3bf8f63e6179076b57c9de660c9f80b5abefe70
- Affected versionversion=1b562b7f9231432da40d12e19786c1bd7df653a7 <6c589aa318023690f1606c666a7fb5f4c1c9c219
- Affected versionversion=1e6d9d87626cf89eeffb4d943db12cb5b10bf961 <7d62ded97db6b7c94c891f704151f372b1ba4688
- Affected versionversion=35d0137305ae2f97260a9047f445bd4434bd6cc7 <1348214fa042a71406964097e743c87a42c85a49
- Affected versionversion=6.1.129 <6.1.135
- Affected versionversion=6.12.13 <6.12.24
- Affected versionversion=6.13.2 <6.13.12
- Affected versionversion=6.14
- Affected versionversion=6.6.76 <6.6.88
- Affected versionversion=7d8947f2153ee9c5ab4cb17861a11cc45f30e8c4 <f86293adce0c201cfabb283ef9d6f21292089bb8
- Affected versionversion=7fefc294204f10a3405f175f4ac2be16d63f135e <5e5e1fcc1b8ed57f902c424c5d9b328a3a19073d
- Affected versionversion=833e9a1c27b82024db7ff5038a51651f48f05e5e <d2718324f9e329b10ddc091fba5a0ba2b9d4d96a
- Affected versionversion=e12f6013d0a69660e8b99bfe381b9546ae667328 <8fadc871a42933aacb7f1ce9ed9a96485e2c9cf4
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upstream deterministic SFQ qdisc reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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