net: openvswitch: fix use-after-free of the flow table mask array
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: 0.15% (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 017dbbf0d6c319a487f68e22f56d91fc787d5525, 035e9c3722067648a99010711d0ce81f42572ef4, 4016ead17acd75312c066ecd47c4b7f0a81ceaa2; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 017dbbf0d6c319a487f68e22f56d91fc787d5525, 035e9c3722067648a99010711d0ce81f42572ef4, 4016ead17acd75312c066ecd47c4b7f0a81ceaa2; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes 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: openvswitch: fix use-after-free of the flow table mask array tbl_mask_array_realloc() retires the old mask_array before it stops being reachable: old = ovsl_dereference(tbl->mask_array); if (old) { ... call_rcu(&old->rcu, mask_array_rcu_cb); } rcu_assign_pointer(tbl->mask_array, new); call_rcu() only waits for read-side critical sections already in flight. tbl->mask_array still points at old between the call_rcu() and the rcu_assign_pointer(), so a reader entering ovs_flow_tbl_lookup_stats() in that window picks up old in a fresh critical section that the pending grace period does not cover. tbl_mask_array_realloc() runs in process context under ovs_mutex, so the window is preemptible and can outlast the grace period. Then mask_array_rcu_cb() frees old before the swap runs: BUG: KASAN: slab-use-after-free in flow_lookup.constprop.0+0x2bf/0x2f0 Read of size 8 at addr ffff888020b3e018 by task poc/741 flow_lookup.constprop.0+0x2bf/0x2f0 ovs_flow_tbl_lookup_stats+0x4a3/0x5c0 ovs_dp_process_packet+0x19c/0x710 ovs_vport_receive+0x243/0x390 internal_dev_xmit+0x81/0x170 Freed by task 728: kfree+0x16a/0x4e0 rcu_core+0x853/0x1030 Publish the new array before retiring the old one. The kfree_rcu() that call_rcu() replaced ran after the swap.
- Published
- Sep 25, 2026
- Updated
- Oct 3, 2026
- EPSS
- 0.2% · 5th percentile
- CWE
- —
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 · 0.2%
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.
—
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
- 5.9affected
- eac87c413bf9794c14d488998a5265ea5b32f04e and later · before 4c98b492e9ed63f9ca3e23566d9a6a4f235944f4affected · git
- eac87c413bf9794c14d488998a5265ea5b32f04e and later · before 4016ead17acd75312c066ecd47c4b7f0a81ceaa2affected · git
- eac87c413bf9794c14d488998a5265ea5b32f04e and later · before 017dbbf0d6c319a487f68e22f56d91fc787d5525affected · git
- eac87c413bf9794c14d488998a5265ea5b32f04e and later · before 76678217cdabc41e3c74c23b45b62086ffb8fe7aaffected · git
- eac87c413bf9794c14d488998a5265ea5b32f04e and later · before cd982e11684def5d4a9fcfd5354de09032828414affected · git
- eac87c413bf9794c14d488998a5265ea5b32f04e and later · before a0d18d21d48a551f82ee344e50efb8a682161489affected · git
- eac87c413bf9794c14d488998a5265ea5b32f04e and later · before 035e9c3722067648a99010711d0ce81f42572ef4affected · git
- eac87c413bf9794c14d488998a5265ea5b32f04e and later · before ba4ba11ed6eb8972c69070417fc27b48deb002e8affected · git
- before 5.9not 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 | all versions | — |
| Debian:12 | linux-6.12 | before 6.12.111-1~deb12u1 | 6.12.111-1~deb12u1 |
| Debian:13 | linux | before 6.12.111-1 | 6.12.111-1 |
| Debian:14 | linux | before 7.2.7-1 | 7.2.7-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
- CVE-2026-74309vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler40Plan
- CVE-2026-74280crypto: marvell/octeontx - fix DMA cleanup using wrong loop index40Plan
- CVE-2026-74279crypto: cavium/cpt - fix DMA cleanup using wrong loop index40Plan
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 | 017dbbf0d6c319a487f68e22f56d91fc787d5525 | Vendor (CNA) |
| Linux Linux | 035e9c3722067648a99010711d0ce81f42572ef4 | Vendor (CNA) |
| Linux Linux | 4016ead17acd75312c066ecd47c4b7f0a81ceaa2 | Vendor (CNA) |
| Linux Linux | 4c98b492e9ed63f9ca3e23566d9a6a4f235944f4 | Vendor (CNA) |
| Linux Linux | 76678217cdabc41e3c74c23b45b62086ffb8fe7a | Vendor (CNA) |
| Linux Linux | a0d18d21d48a551f82ee344e50efb8a682161489 | Vendor (CNA) |
| Linux Linux | ba4ba11ed6eb8972c69070417fc27b48deb002e8 | Vendor (CNA) |
| Linux Linux | cd982e11684def5d4a9fcfd5354de09032828414 | Vendor (CNA) |
| azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| debian:linux | 6.12.111-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.111-1~deb12u1 · Debian:12 | 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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1184 · Sep 28, 2026(Linux Kernel Güvenlik Bildirimi)
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)
—
CVSS 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
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (7 more)Show less
- git.kernel.org/stable/c/035e9c3722067648a99010711d0ce81f42572ef4
- git.kernel.org/stable/c/4016ead17acd75312c066ecd47c4b7f0a81ceaa2
- git.kernel.org/stable/c/4c98b492e9ed63f9ca3e23566d9a6a4f235944f4
- git.kernel.org/stable/c/76678217cdabc41e3c74c23b45b62086ffb8fe7a
- git.kernel.org/stable/c/a0d18d21d48a551f82ee344e50efb8a682161489
- git.kernel.org/stable/c/ba4ba11ed6eb8972c69070417fc27b48deb002e8
- git.kernel.org/stable/c/cd982e11684def5d4a9fcfd5354de09032828414
Vendor advisories and official records. Exploit/PoC links are deliberately left out.