Local privilege escalation via inet6_dev use-after-free
Published Aug 22, 2026 · Updated Aug 25, 2026
Use-after-free in the Linux kernel IPv6 subsystem allows local users to corrupt kernel memory through a multicast source-filter race. The in6_dev_get() helper increments an inet6_dev refcount after RCU lookup without ensuring it remains nonzero, resurrecting an object already queued for freeing. An unprivileged local user can control both sides of the race through IPv6 multicast socket options and virtual-link deletion, causing kernel memory corruption that supports privilege escalation or a crash.
Summary
What happened
Use-after-free in the Linux kernel IPv6 subsystem allows local users to corrupt kernel memory through a multicast source-filter race. The in6_dev_get() helper increments an inet6_dev refcount after RCU lookup without ensuring it remains nonzero, resurrecting an object already queued for freeing. An unprivileged local user can control both sides of the race through IPv6 multicast socket options and virtual-link deletion, causing kernel memory corruption that supports privilege escalation or a crash.
The record
- CVE
- CVE-2026-74630
- Published
- Aug 22, 2026
- Updated
- Aug 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Aug 22, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 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=2.6.19
- Affected versionversion=8814c4b533817df825485ff32ce6ac406c3a54d1 <0e243671bc7b8eaf00f83dd2f4367436dc0cff98
- Affected versionversion=8814c4b533817df825485ff32ce6ac406c3a54d1 <145812b678de9f3b59780173be3c0d22ed60dd93
- Affected versionversion=8814c4b533817df825485ff32ce6ac406c3a54d1 <14e812ab41df0cac033479da835ec9a5de633404
- Affected versionversion=8814c4b533817df825485ff32ce6ac406c3a54d1 <1c206d461c680c3151daa3c89fc26eaf5bf98a7f
- Affected versionversion=8814c4b533817df825485ff32ce6ac406c3a54d1 <680fbd7942185448eadb990a3d10a53eb946b702
- Affected versionversion=8814c4b533817df825485ff32ce6ac406c3a54d1 <785d908f8d21c8bc78b6fb2c2932ab662bf6918a
- Affected versionversion=8814c4b533817df825485ff32ce6ac406c3a54d1 <aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8
- Affected versionversion=8814c4b533817df825485ff32ce6ac406c3a54d1 <cc5bd568f9b7683e60841b6fd02c10d64535bd6e
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
No public exploit references are available in this record.
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
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo