CVE-2026-23184: binder: fix UAF in binder_netlink_report()
In the Linux kernel, the following vulnerability has been resolved:
binder: fix UAF in binder_netlink_report()
Oneway transactions sent to frozen targets via binder_proc_transaction()
return a BR_TRANSACTION_PENDING_FROZEN error but they are still treated
as successful since the target is expected to thaw at some point. It is
then not safe to access 't' after BR_TRANSACTION_PENDING_FROZEN errors
as the transaction could have been consumed by the now thawed target.
This is the case for binder_netlink_report() which derreferences 't'
after a pending frozen error, as pointed out by the following KASAN
report:
==================================================================
BUG: KASAN: slab-use-after-free in binder_netlink_report.isra.0+0x694/0x6c8
Read of size 8 at addr ffff00000f98ba38 by task binder-util/522
CPU: 4 UID: 0 PID: 522 Comm: binder-util Not tainted 6.19.0-rc6-00015-gc03e9c42ae8f #1 PREEMPT
Hardware name: linux,dummy-virt (DT)
Call trace:
binder_netlink_report.isra.0+0x694/0x6c8
binder_transaction+0x66e4/0x79b8
binder_thread_write+0xab4/0x4440
binder_ioctl+0x1fd4/0x2940
[...]
Allocated by task 522:
__kmalloc_cache_noprof+0x17c/0x50c
binder_transaction+0x584/0x79b8
binder_thread_write+0xab4/0x4440
binder_ioctl+0x1fd4/0x2940
[...]
Freed by task 488:
kfree+0x1d0/0x420
binder_free_transaction+0x150/0x234
binder_thread_read+0x2d08/0x3ce4
binder_ioctl+0x488/0x2940
[...]
==================================================================
Instead, make a transaction copy so the data can be safely accessed by
binder_netlink_report() after a pending frozen error. While here, add a
comment about not using t->buffer in binder_netlink_report().
Security readout for executives and security teams
Plain-English summary
CVE-2026-23184 is a Linux kernel Binder use-after-free flaw. A local low-privileged actor could potentially affect confidentiality, integrity, and availability on systems running vulnerable kernel versions. The source bundle names kernel stable fixes, but does not show active exploitation or a standalone workaround.
Executive priority
Treat as high priority for endpoints, devices, or multi-user systems using affected Linux kernels. It is not currently documented here as internet-exploitable or actively exploited, so patch through normal urgent kernel maintenance rather than emergency incident response.
Technical view
The bug is in binder_netlink_report(). After BR_TRANSACTION_PENDING_FROZEN, a Binder transaction may be consumed by a thawed target, making later dereference of t unsafe. KASAN showed slab-use-after-free. The fix copies transaction data before reporting and documents unsafe buffer use.
Likely exposure
Exposure is most relevant to Linux systems running affected 6.18/6.19-era kernels with Binder functionality reachable by local low-privileged users or processes. The provided version metadata is limited and should be validated against vendor kernel packages.
Exploitation context
The CVSS vector is local, low complexity, low privileges, no user interaction, with high confidentiality, integrity, and availability impact. CISA KEV is false in the bundle, and no cited source here reports active exploitation.
Researcher notes
The source evidence is kernel-resolution text and two stable commit references. Affected range formatting appears incomplete, so avoid overclaiming exact version boundaries without vendor package confirmation. Analysis should focus on Binder reachability, local privilege context, and whether fixes are backported.
Mitigation direction
Update to a vendor kernel containing the referenced stable fixes.
Prioritize systems where untrusted local users or workloads can reach Binder.
Check Linux distribution or device vendor advisories for backported package names.
If immediate patching is unavailable, review vendor guidance for temporary risk reduction.
Validation and detection
Inventory Linux kernel versions and map them to vendor fixed builds.
Confirm whether Binder is enabled and exposed on relevant systems.
Review vendor changelogs for the referenced stable commit identifiers.
Monitor KASAN, kernel oops, or Binder-related crashes on affected systems.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
cve · low confidence lookup
CVE-2026-23184 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
1CVSS vectors
3Timeline events
0ADP providers
3Source links
CVSS vector scores
1 official score
We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.