Dropped refcount update on Binder thread exit in Linux kernel
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from CNA.
Summary
The rust_binder driver in the Linux kernel, from 6.18, drops a pending node refcount update when a thread exits through BINDER_THREAD_EXIT. Because the cancel handlers for nodes did nothing, the node's delivery and count states fall out of sync and userspace is not notified. As a result, the node may never be freed from the process's nodes tree after all external references are dropped.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: rust_binder: reschedule node refcount update on thread exit When a thread exits via BINDER_THREAD_EXIT, its pending work items are cancelled. If a thread exits while holding a pending node refcount increment (e.g. pushed as deferred work to that thread), the refcount increment was previously dropped because Node::cancel() and NodeWrapper::cancel() were no-ops. Dropping the refcount update leaves the node's delivery state and count state desynchronized, and userspace will not receive the notification, which can cause the node to never be freed from the process's nodes tree when all external references are dropped. Fix this by implementing DeliverToRead::cancel() for Node and NodeWrapper to move the pending refcount update to the process's work queue on thread exit so another thread can deliver it to userspace.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update the Linux kernel to 6.18.57, 7.2.11 or 7.3, which contain the fix.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 6.18.57, 7.2.11, 7.3
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
Not affected: 6 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-23 Threatist record created from CVE-2026-99075
- 2026-10-23 Alias added: GHSA-gxfj-h7rr-9wq9
- 2026-10-26 Affected versions changed · Red Hat
- 2026-10-26 CVSS score added · Red Hat
References
More Linux vulnerabilities
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- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-99075 · CVE Program
- CVE-2026-99075 · NVD
- FIRST EPSS
- GHSA-gxfj-h7rr-9wq9 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-99075 · Red Hat security data · CC BY 4.0
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