CVE-2026-23274: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels
Noroxi assessment
Priority: Monitor (action score 31/100)
- 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: 0.18% (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 144f88054ba0180467356f40895bd660b5dceeec, 28c7cfaf0c0ab17cbd7754092116fd1af45271f9, 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf; azl3 kernel 6.6.126.1-1 on Azure Linux 3.0 6.6.130.1-1.
Low priority for now. Upgrade to Linux Linux 144f88054ba0180467356f40895bd660b5dceeec, 28c7cfaf0c0ab17cbd7754092116fd1af45271f9, 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf; azl3 kernel 6.6.126.1-1 on Azure Linux 3.0 6.6.130.1-1 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: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels IDLETIMER revision 0 rules reuse existing timers by label and always call mod_timer() on timer->timer. If the label was created first by revision 1 with XT_IDLETIMER_ALARM, the object uses alarm timer semantics and timer->timer is never initialized. Reusing that object from revision 0 causes mod_timer() on an uninitialized timer_list, triggering debugobjects warnings and possible panic when panic_on_warn=1. Fix this by rejecting revision 0 rule insertion when an existing timer with the same label is of ALARM type.
- BDU:2026-09456
- SUSE-SU-2026:1342-1
- SUSE-SU-2026:1557-1
- SUSE-SU-2026:1563-1
- SUSE-SU-2026:1574-1
- SUSE-SU-2026:1575-1
- SUSE-SU-2026:1606-1
- SUSE-SU-2026:22030-1
- SUSE-SU-2026:22031-1
- SUSE-SU-2026:22033-1
- SUSE-SU-2026:22035-1
- SUSE-SU-2026:22038-1
- SUSE-SU-2026:22039-1
- SUSE-SU-2026:22040-1
- SUSE-SU-2026:22042-1
- Published
- Mar 20, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.1% · 7th percentile
- CWE
- CWE-758
Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 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
- —
- CNA · Linux
- 7.8
- NVD has not scored this yet; the score shown is the CNA’s.
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.
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Noroxi 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 |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel5.7 and later · before 5.10.253
- linux linux kernel5.11 and later · before 5.15.203
- linux linux kernel5.16 and later · before 6.1.167
- linux linux kernel6.2 and later · before 6.6.130
- linux linux kernel6.7 and later · before 6.12.78
- linux linux kernel6.13 and later · before 6.18.19
- linux linux kernel6.19 and later · before 6.19.9
- linux linux kernel7.0
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
- 5.7affected
- 68983a354a655c35d3fb204489d383a2a051fda7 and later · before 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44affected · git
- 68983a354a655c35d3fb204489d383a2a051fda7 and later · before 144f88054ba0180467356f40895bd660b5dceeecaffected · git
- 68983a354a655c35d3fb204489d383a2a051fda7 and later · before 28c7cfaf0c0ab17cbd7754092116fd1af45271f9affected · git
- 68983a354a655c35d3fb204489d383a2a051fda7 and later · before 54080355999381fed4a26129579a5765bab87491affected · git
- 68983a354a655c35d3fb204489d383a2a051fda7 and later · before 5e7ece24c5cb75a60402aad4d803c7898ea40aa9affected · git
- 68983a354a655c35d3fb204489d383a2a051fda7 and later · before f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1affected · git
- 68983a354a655c35d3fb204489d383a2a051fda7 and later · before f228b9ae2a7e84d1153616d8e71c4236cb1f1309affected · git
- 68983a354a655c35d3fb204489d383a2a051fda7 and later · before 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cfaffected · git
- before 5.7not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.170-1 | 6.1.170-1 |
| Debian:13 | linux | before 6.12.85-1 | 6.12.85-1 |
| Debian:14 | linux | before 6.19.10-1 | 6.19.10-1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-64kb | before 5.14.21-150400.24.200.1 | 5.14.21-150400.24.200.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-docs | before 5.14.21-150400.24.200.1 | 5.14.21-150400.24.200.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-obs-build | before 5.14.21-150400.24.200.1 | 5.14.21-150400.24.200.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-syms | before 5.14.21-150400.24.200.1 | 5.14.21-150400.24.200.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-64kb | before 5.14.21-150500.55.144.1 | 5.14.21-150500.55.144.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-docs | before 5.14.21-150500.55.144.1 | 5.14.21-150500.55.144.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-obs-build | before 5.14.21-150500.55.144.1 | 5.14.21-150500.55.144.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-syms | before 5.14.21-150500.55.144.1 | 5.14.21-150500.55.144.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_50 | before 1-150400.9.3.1 | 1-150400.9.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_37 | before 1-150500.11.3.1 | 1-150500.11.3.1 |
| SUSE:Linux Enterprise Micro 5.2 | kernel-default | before 5.3.18-150300.59.241.1 | 5.3.18-150300.59.241.1 |
| SUSE:Linux Enterprise Micro 5.2 | kernel-default-base | before 5.3.18-150300.59.241.1.150300.18.144.1 | 5.3.18-150300.59.241.1.150300.18.144.1 |
| SUSE:Linux Enterprise Micro 5.2 | kernel-rt | before 5.3.18-150300.241.1 | 5.3.18-150300.241.1 |
| SUSE:Linux Enterprise Micro 5.2 | kernel-source | before 5.3.18-150300.59.241.1 | 5.3.18-150300.59.241.1 |
| SUSE:Linux Enterprise Micro 5.2 | kernel-source-rt | before 5.3.18-150300.241.1 | 5.3.18-150300.241.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-default | before 5.14.21-150400.24.200.1 | 5.14.21-150400.24.200.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-default-base | before 5.14.21-150400.24.200.1.150400.24.102.1 | 5.14.21-150400.24.200.1.150400.24.102.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-rt | before 5.14.21-150400.15.148.1 | 5.14.21-150400.15.148.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-source | before 5.14.21-150400.24.200.1 | 5.14.21-150400.24.200.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-source-rt | before 5.14.21-150400.15.148.1 | 5.14.21-150400.15.148.1 |
| SUSE:Linux Enterprise Micro 5.5 | kernel-default | before 5.14.21-150500.55.144.1 | 5.14.21-150500.55.144.1 |
+13
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-2026-23272Mar 20, 2026 · netfilter: nf_tables: unconditionally bump set->nelems before insertion31Monitor
- ← EarlierCVE-2026-23273Mar 20, 2026 · macvlan: observe an RCU grace period in macvlan_common_newlink() error path31Monitor
- Later →CVE-2026-23275Mar 20, 2026 · io_uring: ensure ctx->rings is stable for task work flags manipulation31Monitor
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 | 144f88054ba0180467356f40895bd660b5dceeec | Vendor (CNA) |
| Linux Linux | 28c7cfaf0c0ab17cbd7754092116fd1af45271f9 | Vendor (CNA) |
| Linux Linux | 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf | Vendor (CNA) |
| Linux Linux | 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44 | Vendor (CNA) |
| Linux Linux | 54080355999381fed4a26129579a5765bab87491 | Vendor (CNA) |
| Linux Linux | 5e7ece24c5cb75a60402aad4d803c7898ea40aa9 | Vendor (CNA) |
| Linux Linux | f228b9ae2a7e84d1153616d8e71c4236cb1f1309 | Vendor (CNA) |
| Linux Linux | f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1 | Vendor (CNA) |
| azl3 kernel 6.6.126.1-1 on Azure Linux 3.0 | 6.6.130.1-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| debian:linux | 6.1.170-1 · Debian:12 | Package registry (OSV) |
| suse:kernel-64kb | 5.14.21-150400.24.200.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-default | 5.3.18-150300.59.241.1 · SUSE:Linux Enterprise Micro 5.2 | Package registry (OSV) |
| suse:kernel-default-base | 5.3.18-150300.59.241.1.150300.18.144.1 · SUSE:Linux Enterprise Micro 5.2 | Package registry (OSV) |
| suse:kernel-docs | 5.14.21-150400.24.200.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-livepatch-SLE15-SP4_Update_50 | 1-150400.9.3.1 · SUSE:Linux Enterprise Live Patching 15 SP4 | Package registry (OSV) |
| suse:kernel-livepatch-SLE15-SP5_Update_37 | 1-150500.11.3.1 · SUSE:Linux Enterprise Live Patching 15 SP5 | Package registry (OSV) |
| suse:kernel-obs-build | 5.14.21-150400.24.200.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-rt | 5.14.21-150400.15.148.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-source | 5.3.18-150300.59.241.1 · SUSE:Linux Enterprise Micro 5.2 | Package registry (OSV) |
| suse:kernel-source-rt | 5.14.21-150400.15.148.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-syms | 5.14.21-150400.24.200.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-zfcpdump | 5.14.21-150400.24.200.1 · SUSE:Linux Enterprise Server 15 SP4-LTSS | Package registry (OSV) |
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.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
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
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-758 · Reliance on Undefined, Unspecified, or Implementation-Defined BehaviorCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (11 more)Show less
- git.kernel.org/stable/c/28c7cfaf0c0ab17cbd7754092116fd1af45271f9
- git.kernel.org/stable/c/329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf
- git.kernel.org/stable/c/32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44
- git.kernel.org/stable/c/54080355999381fed4a26129579a5765bab87491
- git.kernel.org/stable/c/5e7ece24c5cb75a60402aad4d803c7898ea40aa9
- git.kernel.org/stable/c/f228b9ae2a7e84d1153616d8e71c4236cb1f1309
- git.kernel.org/stable/c/f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1
- cert-portal.siemens.com/productcert/html/ssa-019113.html
- cert-portal.siemens.com/productcert/html/ssa-082556.html
- cert-portal.siemens.com/productcert/html/ssa-457936.html
- cert-portal.siemens.com/productcert/html/ssa-784472.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.