CVE-2026-74398

CRITICALCVSS 9.8/10EPSS 0.18%

Last modified

CVE-2026-74398 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: ipv6: addrconf: bail out of dad_failure when state is no longer POSTDAD addrconf_dad_failure() transitions ifp->state from DAD to POSTDAD via addrconf_dad_end(), which drops ifp->lock on return. The lock is re-acquired after net_info_ratelimited(). EPSS estimates a 0.18% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: addrconf: bail out of dad_failure when state is no longer POSTDAD addrconf_dad_failure() transitions ifp->state from DAD to POSTDAD via addrconf_dad_end(), which drops ifp->lock on return. The lock is re-acquired after net_info_ratelimited(). A concurrent ipv6_del_addr() can take the lock in that window, set ifp->state to DEAD and run list_del_rcu(&ifp->if_list). addrconf_dad_failure() then overwrites DEAD with ERRDAD at errdad: and schedules a new dad_work. The work calls ipv6_del_addr() again, hitting the already-poisoned list entry: general protection fault: 0000 [#1] SMP NOPTI CPU: 4 PID: 217 Comm: kworker/4:1 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:ipv6_del_addr+0xe9/0x280 RAX: dead000000000122 Call Trace: addrconf_dad_stop+0x113/0x140 addrconf_dad_work+0x28c/0x430 process_one_work+0x1eb/0x3b0 worker_thread+0x4d/0x400 kthread+0x104/0x140 ret_from_fork+0x35/0x40 Fold the addrconf_dad_end() logic into addrconf_dad_failure() under a single ifp->lock critical section. The STABLE_PRIVACY branch temporarily drops ifp->lock around address regeneration, so at lock_errdad: verify the state is still POSTDAD before transitioning to ERRDAD; bail out otherwise to avoid overwriting a state set by another path while the lock was released.

Metrics

CVSS 3.1
9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.18%

7.5th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= c15b1ccadb323ea50023e8f1cca2954129a62b51, < 47b05836705b63dab93d9ac7c69a3a507375ef80; >= c15b1ccadb323ea50023e8f1cca2954129a62b51, < d21be7d051012c6b572fa4e3334443c250216f7b; >= c15b1ccadb323ea50023e8f1cca2954129a62b51, < 875c284c0f98b042bb97abad460f63a24c977f88; >= c15b1ccadb323ea50023e8f1cca2954129a62b51, < 8ed0ce9ea58d677d1bac92614ee5f60f8ea57363; >= c15b1ccadb323ea50023e8f1cca2954129a62b51, < 3bdc86d89fd6c6523753fa6f42fcfaf30ee699cb; >= c15b1ccadb323ea50023e8f1cca2954129a62b51, < b61af0268e3d1308c466bf0be5dced844eafc1ef; >= c15b1ccadb323ea50023e8f1cca2954129a62b51, < e889aa99ad3ed48bb0ddcff6475b17542532d18b; >= c15b1ccadb323ea50023e8f1cca2954129a62b51, < 627ac78f2741e2ebd2225e2e953b6964a8a9182f; 835b474b8f70fa68d68abffad37378e92f661802; >= 3.10.105, < 3.11
LinuxLinux3.14

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-74398?
In the Linux kernel, the following vulnerability has been resolved: ipv6: addrconf: bail out of dad_failure when state is no longer POSTDAD addrconf_dad_failure() transitions ifp->state from DAD to POSTDAD via addrconf_dad_end(), which drops ifp->lock on return. The lock is re-acquired after net_info_ratelimited(). A concurrent ipv6_del_addr() can take the lock in that window, set ifp->state to DEAD and run list_del_rcu(&ifp->if_list). addrconf_dad_failure() then overwrites DEAD with ERRDAD at errdad: and schedules a new dad_work. The work calls ipv6_del_addr() again, hitting the already-poisoned list entry: general protection fault: 0000 [#1] SMP NOPTI CPU: 4 PID: 217 Comm: kworker/4:1 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:ipv6_del_addr+0xe9/0x280 RAX: dead000000000122 Call Trace: addrconf_dad_stop+0x113/0x140 addrconf_dad_work+0x28c/0x430 process_one_work+0x1eb/0x3b0 worker_thread+0x4d/0x400 kthread+0x104/0x140 ret_from_fork+0x35/0x40 Fold the addrconf_dad_end() logic into addrconf_dad_failure() under a single ifp->lock critical section. The STABLE_PRIVACY branch temporarily drops ifp->lock around address regeneration, so at lock_errdad: verify the state is still POSTDAD before transitioning to ERRDAD; bail out otherwise to avoid overwriting a state set by another path while the lock was released.
How severe is CVE-2026-74398?
CVE-2026-74398 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.
How do I fix CVE-2026-74398?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST