net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 4 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag This is more of a preventive patch to make the code more consistent and to prevent possible exploits that employ child qlen manipulations on qfq. use cl_is_active instead of relying on the child qdisc's qlen to determine class activation.
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 | 3.8 and later | 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8, 6.19 | Patch available | CNA |
- Linux VendorLinux Affected 3.8 and later Fixed in 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8, 6.19 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 3.8 to before 5.10.249; 5.11 to before 5.15.199; 5.16 to before 6.1.162; 6.2 to before 6.6.122; 6.7 to before 6.12.68; 6.13 to before 6.18.8 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* | 6.19 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* | 6.19 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* | 6.19 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* | 6.19 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* | 6.19 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:* | 6.19 rc6 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.8 to before 5.10.249; 5.11 to before 5.15.199; 5.16 to before 6.1.162; 6.2 to before 6.6.122; 6.7 to before 6.12.68; 6.13 to before 6.18.8 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* Versions 6.19 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* Versions 6.19 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* Versions 6.19 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* Versions 6.19 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* Versions 6.19 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:* Versions 6.19 rc6 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8, 6.19
Red Hat 2 advisories
- RHSA-2026:75747 Released 2026-10-05 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.171.1.el8_10, kernel-4.18.0-553.171.1.el8_10, kernel-abi-stablelists-4.18.0-553.171.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.171.1.el8_10
- RHSA-2026:75746 Released 2026-10-05 · Red Hat rating Importantkernel-rt security, bug fix, and enhancement update
- Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-core-4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-debug-4.18.0-553.171.1.rt7.512.el8_10 +9
- Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-core-4.18.0-553.171.1.rt7.512.el8_10, kernel-rt-debug-4.18.0-553.171.1.rt7.512.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 BaseOS (v. 8) | Fixed | RHSA-2026:75747 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2026:75747 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2026:75746 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2026:75746 |
Not affected: 2 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-23105
- 2026-10-03 Alias added: GHSA-jvw7-84v9-fr93
- 2026-10-05 Fix available: RHSA-2026:75746 · Red Hat
- 2026-10-05 Fix available: RHSA-2026:75747 · Red Hat
- 2026-10-05 Fix available: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8), Red Hat Enterprise Linux NFV (v. 8) +1 · Red Hat
- 2026-10-19 Weakness changed · CISA ADP
References
Patch 7
- https://git.kernel.org/stable/c/fac2c67bb2bb732eae4283e45fc338af7e08c254
- https://git.kernel.org/stable/c/b8c24cf5268fb3bfb8d16324c3dbb985f698c835
- https://git.kernel.org/stable/c/f27047abf7cac1b6f90c3ad60de21ef9f717c26d
- https://git.kernel.org/stable/c/93b8635974fb050c43d07e35e5edfe6e685ca28a
- https://git.kernel.org/stable/c/abd9fc26ea577561a5ef6241a1b058755ffdad0c
- https://git.kernel.org/stable/c/77f1afd0bb4d5da95236f6114e6d0dfcde187ff6
- https://git.kernel.org/stable/c/d837fbee92453fbb829f950c8e7cf76207d73f33
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Sources
- CVE-2026-23105 · CVE Program
- CVE-2026-23105 · NVD
- FIRST EPSS
- GHSA-jvw7-84v9-fr93 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-23105 · 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