Linux Kernel up to 7.2.5 cuse cuse_exit use after free

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 7.4 | $0-$5k | 0.00 |
Summary
A vulnerability was found in Linux Kernel up to 7.2.5. It has been classified as critical. This issue affects the function cuse_exit of the component cuse. This manipulation causes use after free.
This vulnerability appears as CVE-2026-90140. The attack requires local access. There is no available exploit.
Upgrading the affected component is recommended.
Details
A vulnerability was found in Linux Kernel up to 7.2.5. It has been declared as critical. Affected by this vulnerability is the function cuse_exit of the component cuse. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:
In the Linux kernel, the following vulnerability has been resolved: cuse: wait for pending RCU callbacks on module exit Since commit 053fc4f755ad ("fuse: fix UAF in rcu pathwalks"), fuse_conn_put() frees the fuse_conn through call_rcu() rather than synchronously. For cuse, fc->release is cuse_fc_release(), which lives in the cuse module. If the module is removed before the RCU grace period ends, the callback jumps into freed module memory: userspace / module unload | RCU softirq ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ close(/dev/cuse) | cuse_channel_release() | fuse_dev_release() | fuse_conn_put(fch->conn) | call_rcu(delayed_release) ------+---> callback queued | rmmod cuse | cuse_exit() | cuse_channel_destroy() | ... | return | | <module text freed> | | rcu_do_batch() | delayed_release() | fc->release() | -> cuse_fc_release() | ^^^ freed text! The freed module text is unmapped by vfree(), so the jump into the stale callback triggers a page-fault Oops. If the virtual address is subsequently reused, the callback could execute unrelated code (undefined behaviour). Fix this by calling rcu_barrier() in cuse_exit() so that any pending fuse_conn release callback completes before the module is removed.
It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-90140 since 09/11/2026. The exploitation appears to be easy. Attacking locally is a requirement. Additional levels of successful authentication are necessary for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/17/2026).
Upgrading to version 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch 7fe415e1cd8fa875be263670c0ab47109818abb6/45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e/ac5c499413385cea3e0220d6050408d50842891d/a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9/389bd349ddbcf90dbd8a4f2a4ab6e552d53df134/c40f3f24839f8404325a2099e26c2a04786ae309/4deb3edead0c0e172cc7349e8855d741d3c5e162 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.
Be aware that VulDB is the high quality source for vulnerability data.
Product
Type
Vendor
Name
Version
- 5.15.220
- 6.1.187
- 6.6.156
- 6.12.109
- 6.18.0
- 6.18.1
- 6.18.2
- 6.18.3
- 6.18.4
- 6.18.5
- 6.18.6
- 6.18.7
- 6.18.8
- 6.18.9
- 6.18.10
- 6.18.11
- 6.18.12
- 6.18.13
- 6.18.14
- 6.18.15
- 6.18.16
- 6.18.17
- 6.18.18
- 6.18.19
- 6.18.20
- 6.18.21
- 6.18.22
- 6.18.23
- 6.18.24
- 6.18.25
- 6.18.26
- 6.18.27
- 6.18.28
- 6.18.29
- 6.18.30
- 6.18.31
- 6.18.32
- 6.18.33
- 6.18.34
- 6.18.35
- 6.18.36
- 6.18.37
- 6.18.38
- 6.18.39
- 6.18.40
- 6.18.41
- 6.18.42
- 6.18.43
- 6.18.44
- 6.18.45
- 6.18.46
- 6.18.47
- 6.18.48
- 6.18.49
- 6.18.50
- 6.18.51
- 7.2.0
- 7.2.1
- 7.2.2
- 7.2.3
- 7.2.4
- 7.2.5
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔒VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 7.7VulDB Meta Temp Score: 7.4
VulDB Base Score: 7.7
VulDB Temp Score: 7.4
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv2
| AV | AC | Au | C | I | A |
|---|---|---|---|---|---|
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
|---|---|---|---|---|---|
| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploiting
Class: Use after freeCWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒
Physical: Partially
Local: Yes
Remote: Partially
Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒
| 0-Day | Unlock | Unlock | Unlock | Unlock |
|---|---|---|---|---|
| Today | Unlock | Unlock | Unlock | Unlock |
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔒
Upgrade: Kernel 5.15.221/6.1.188/6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: 7fe415e1cd8fa875be263670c0ab47109818abb6/45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e/ac5c499413385cea3e0220d6050408d50842891d/a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9/389bd349ddbcf90dbd8a4f2a4ab6e552d53df134/c40f3f24839f8404325a2099e26c2a04786ae309/4deb3edead0c0e172cc7349e8855d741d3c5e162
Timeline
09/11/2026 CVE reserved09/17/2026 Advisory disclosed
09/17/2026 VulDB entry created
09/17/2026 VulDB entry last update
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2026-90140 (🔒)
GCVE (CVE): GCVE-0-2026-90140
GCVE (VulDB): GCVE-100-406663
Entry
Created: 09/17/2026 20:00Changes: 09/17/2026 20:00 (59)
Complete: 🔍
Cache ID: 216::103
Be aware that VulDB is the high quality source for vulnerability data.
No comments yet. Languages: en.
Please log in to comment.