CVE-2026-23105: net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag
Noroxi assessment
Priority: Monitor (action score 22/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.14% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Linux Linux 77f1afd0bb4d5da95236f6114e6d0dfcde187ff6, 93b8635974fb050c43d07e35e5edfe6e685ca28a, abd9fc26ea577561a5ef6241a1b058755ffdad0c.
- Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 5.5.
Low priority for now. Upgrade to Linux Linux 77f1afd0bb4d5da95236f6114e6d0dfcde187ff6, 93b8635974fb050c43d07e35e5edfe6e685ca28a, abd9fc26ea577561a5ef6241a1b058755ffdad0c or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Feb 4, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.1% · 3th percentile
- CWE
- CWE-20
Report tools
Action score
22
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.5
- CNA · Linux
- 7.8
- 2.3 point gap
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 3.8affected
- 462dbc9101acd38e92eda93c0726857517a24bbd and later · before fac2c67bb2bb732eae4283e45fc338af7e08c254affected · git
- 462dbc9101acd38e92eda93c0726857517a24bbd and later · before b8c24cf5268fb3bfb8d16324c3dbb985f698c835affected · git
- 462dbc9101acd38e92eda93c0726857517a24bbd and later · before f27047abf7cac1b6f90c3ad60de21ef9f717c26daffected · git
- 462dbc9101acd38e92eda93c0726857517a24bbd and later · before 93b8635974fb050c43d07e35e5edfe6e685ca28aaffected · git
- 462dbc9101acd38e92eda93c0726857517a24bbd and later · before abd9fc26ea577561a5ef6241a1b058755ffdad0caffected · git
- 462dbc9101acd38e92eda93c0726857517a24bbd and later · before 77f1afd0bb4d5da95236f6114e6d0dfcde187ff6affected · git
- 462dbc9101acd38e92eda93c0726857517a24bbd and later · before d837fbee92453fbb829f950c8e7cf76207d73f33affected · git
- before 3.8not affected · semver
- 5.10.249 and later · up to and including 5.10.*not affected · semver
Affected versions · NVD (7)
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel3.8 and later · before 5.10.249
- linux linux kernel5.11 and later · before 5.15.199
- linux linux kernel5.16 and later · before 6.1.162
- linux linux kernel6.2 and later · before 6.6.122
- linux linux kernel6.7 and later · before 6.12.68
- linux linux kernel6.13 and later · before 6.18.8
- linux linux kernel6.19
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | bpftool | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-abi-stablelists | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-core | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-cross-headers | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-debug | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-debug-core | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-debug-devel | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules-extra | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-devel | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-doc | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-headers | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-modules | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-modules-extra | before 4.18.0-553.171.1.el8_10 | 4.18.0-553.171.1.el8_10 |
| AlmaLinux:8 | kernel-rt | before 4.18.0-553.171.1.rt7.512.el8_10 | 4.18.0-553.171.1.rt7.512.el8_10 |
| AlmaLinux:8 | kernel-rt-core | before 4.18.0-553.171.1.rt7.512.el8_10 | 4.18.0-553.171.1.rt7.512.el8_10 |
| AlmaLinux:8 | kernel-rt-debug | before 4.18.0-553.171.1.rt7.512.el8_10 | 4.18.0-553.171.1.rt7.512.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-core | before 4.18.0-553.171.1.rt7.512.el8_10 | 4.18.0-553.171.1.rt7.512.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-devel | before 4.18.0-553.171.1.rt7.512.el8_10 | 4.18.0-553.171.1.rt7.512.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules | before 4.18.0-553.171.1.rt7.512.el8_10 | 4.18.0-553.171.1.rt7.512.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules-extra | before 4.18.0-553.171.1.rt7.512.el8_10 | 4.18.0-553.171.1.rt7.512.el8_10 |
| AlmaLinux:8 | kernel-rt-devel | before 4.18.0-553.171.1.rt7.512.el8_10 | 4.18.0-553.171.1.rt7.512.el8_10 |
| AlmaLinux:8 | kernel-rt-modules | before 4.18.0-553.171.1.rt7.512.el8_10 | 4.18.0-553.171.1.rt7.512.el8_10 |
+65
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2026-23103Feb 4, 2026 · ipvlan: Make the addrs_lock be per port22Monitor
- ← EarlierCVE-2026-23104Feb 4, 2026 · ice: fix devlink reload call trace22Monitor
- Later →CVE-2026-23107Feb 4, 2026 · arm64/fpsimd: signal: Allocate SSVE storage when restoring ZA22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 77f1afd0bb4d5da95236f6114e6d0dfcde187ff6 | Vendor (CNA) |
| Linux Linux | 93b8635974fb050c43d07e35e5edfe6e685ca28a | Vendor (CNA) |
| Linux Linux | abd9fc26ea577561a5ef6241a1b058755ffdad0c | Vendor (CNA) |
| Linux Linux | b8c24cf5268fb3bfb8d16324c3dbb985f698c835 | Vendor (CNA) |
| Linux Linux | d837fbee92453fbb829f950c8e7cf76207d73f33 | Vendor (CNA) |
| Linux Linux | f27047abf7cac1b6f90c3ad60de21ef9f717c26d | Vendor (CNA) |
| Linux Linux | fac2c67bb2bb732eae4283e45fc338af7e08c254 | Vendor (CNA) |
| almalinux:bpftool | 4.18.0-553.171.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel | 4.18.0-553.171.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-core | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-core | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-devel | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-modules | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-modules-extra | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-devel | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-modules | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-modules-extra | 4.18.0-553.171.1.rt7.512.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| debian:linux | 6.1.162-1 · Debian:12 | Package registry (OSV) |
| red hat:kernel-rt | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-core | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-core | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-debuginfo | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-devel | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-kvm | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-modules | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-modules-extra | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debuginfo | 0:4.18.0-553.171.1.rt7.512.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
+4
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-46115113 days apartblock: add pgmap check to biovec_phys_mergeable39Monitor
- CVE-2026-53221141 days apartip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()39Monitor
- CVE-2026-64037165 days apartwifi: iwlwifi: mld: fix TSO segmentation explosion when AMSDU is disabled39Monitor
- CVE-2026-64046165 days apartnet: tls: prevent chain-after-chain in plain text SG39Monitor
- CVE-2026-4311491 days apartnetfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry37Monitor
- CVE-2026-46266119 days apartinet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP36Monitor
Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · public bounty program.
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (6 more)Show less
- git.kernel.org/stable/c/93b8635974fb050c43d07e35e5edfe6e685ca28a
- git.kernel.org/stable/c/abd9fc26ea577561a5ef6241a1b058755ffdad0c
- git.kernel.org/stable/c/b8c24cf5268fb3bfb8d16324c3dbb985f698c835
- git.kernel.org/stable/c/d837fbee92453fbb829f950c8e7cf76207d73f33
- git.kernel.org/stable/c/f27047abf7cac1b6f90c3ad60de21ef9f717c26d
- git.kernel.org/stable/c/fac2c67bb2bb732eae4283e45fc338af7e08c254
Vendor advisories and official records. Exploit/PoC links are deliberately left out.