fuse: re-lock request before returning from fuse_ref_folio()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 16 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: fuse: re-lock request before returning from fuse_ref_folio() fuse_ref_folio() unlocks the request but does not re-lock it before returning. fuse_chan_abort() can end the request and the async end callback (eg fuse_writepage_free()) can free the args while the subsequent copy chain logic after fuse_ref_folio() accesses them, leading to use-after-free issues. Fix this by locking the request in fuse_ref_folio() before returning.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 2.6.35 and later | 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.35 and later Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 2.6.35 to before 5.10.261; 5.11 to before 5.15.212; 5.16 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 2.6.35 to before 5.10.261; 5.11 to before 5.15.212; 5.16 to before 6.1.178; 6.2 to before 6.6.145; 6.7 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2
Red Hat 4 advisories
- RHSA-2026:90365 Released 2026-10-26 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.61.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.61.1.el9_8, kernel-64k-devel-5.14.0-687.61.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.61.1.el9_8, kernel-64k-5.14.0-687.61.1.el9_8, kernel-64k-core-5.14.0-687.61.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.61.1.el9_8, libperf-5.14.0-687.61.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.61.1.el9_8, kernel-rt-64k-5.14.0-687.61.1.el9_8, kernel-rt-64k-core-5.14.0-687.61.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.61.1.el9_8, kernel-rt-core-5.14.0-687.61.1.el9_8, kernel-rt-debug-5.14.0-687.61.1.el9_8 +9
- RHSA-2026:88477 Released 2026-10-23 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- 10Base-SMTV kernel-modules-internal-6.12.0-211.68.1.el10_2
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.68.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.68.1.el10_2, kernel-64k-devel-6.12.0-211.68.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.68.1.el10_2, kernel-64k-6.12.0-211.68.1.el10_2, kernel-64k-core-6.12.0-211.68.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.68.1.el10_2, libperf-6.12.0-211.68.1.el10_2
- Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.68.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.68.1.el10_2, kernel-rt-64k-6.12.0-211.68.1.el10_2, kernel-rt-64k-core-6.12.0-211.68.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.68.1.el10_2, kernel-rt-core-6.12.0-211.68.1.el10_2, kernel-rt-debug-6.12.0-211.68.1.el10_2 +9
- RHSA-2026:87375 Released 2026-10-21 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.177.1.el8_10, kernel-4.18.0-553.177.1.el8_10, kernel-abi-stablelists-4.18.0-553.177.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.177.1.el8_10
Show 1 more Red Hat advisories
- RHSA-2026:87374 Released 2026-10-21 · Red Hat rating Importantkernel-rt security update
- Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core-4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-4.18.0-553.177.1.rt7.518.el8_10 +9
- Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core-4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-4.18.0-553.177.1.rt7.518.el8_10 +7
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| 10Base-SMTV | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:90365 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:87375 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:90365 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2026:87375 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:90365 |
| Red Hat Enterprise Linux Hidden (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2026:87374 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2026:87374 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:90365 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:88477 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:90365 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64266
- 2026-10-03 Alias added: GHSA-x828-8hm7-w4xw
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-20 Weakness changed · CISA ADP
- 2026-10-22 Fix available: RHSA-2026:87374 · Red Hat
- 2026-10-22 Fix available: RHSA-2026:87375 · Red Hat
- 2026-10-23 Fix available: RHSA-2026:88477 · Red Hat
- 2026-10-23 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) +8 · Red Hat
- 2026-10-27 Fix available: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) +2 · Red Hat
- 2026-10-29 Fix available: RHSA-2026:90365 · Red Hat
References
Patch 8
- https://git.kernel.org/stable/c/1f9156714592356b4fda57beac7eab9c2a462dd3
- https://git.kernel.org/stable/c/5630da218a45ba80f0aba0846cbe8aa655da122b
- https://git.kernel.org/stable/c/1ca605cfa59377f0143fb35b5b01360f37d1b7c4
- https://git.kernel.org/stable/c/0e4a5a000123d81234e27a2f8187688cf608f755
- https://git.kernel.org/stable/c/e6aa539720c3d8def69683ed0c07cf9faea4e8be
- https://git.kernel.org/stable/c/be353caffa8640f5e25fb3714ce8b0cef5e410e5
- https://git.kernel.org/stable/c/65a1c2551f7e16085acbb54aedde1feaa559ba7a
- https://git.kernel.org/stable/c/b5befa80fdbe287a98480effed9564712924add5
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Sources
- CVE-2026-64266 · CVE Program
- CVE-2026-64266 · NVD
- FIRST EPSS
- GHSA-x828-8hm7-w4xw · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64266 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences