CVE-2026-98026: net: bridge: mcast: properly convert mglist to rcu
Noroxi assessment
Priority: Monitor (action score 0/100)
- 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: 0.16% (FIRST EPSS).
- Fixed version: Linux Linux 37cb9a81600da8250f24e25edc07253b62353cbe, 38ab2a435001a3c4dbeb70a52f5921e1ccd66f55, 4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 37cb9a81600da8250f24e25edc07253b62353cbe, 38ab2a435001a3c4dbeb70a52f5921e1ccd66f55, 4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 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: net: bridge: mcast: properly convert mglist to rcu Sashiko reported a bug [1] that br_multicast_del_port_group unlists the port group not using proper rcu helper that preserves the next pointer and after that immediately frees the port group without waiting for rcu grace period. The only rcu walker of mglist is br_multicast_list_adjacent() and it turns out that function has always been buggy because mglist was never properly converted to RCU. Fix it by converting it to rcu and moving its initialization after eth_addr's. Initializing p->next can use RCU_INIT_POINTER because we have a barrier from the hlist_add_head_rcu call later, besides we're initializing an unpublished structure anyway. [1] https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260826014200.362304-1-littleddfu%40gmail.com
- Published
- Sep 25, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.1% · 6th percentile
- CWE
- —
Report tools
Action score
0
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
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.
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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
- 3.16affected
- 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980 and later · before 37cb9a81600da8250f24e25edc07253b62353cbeaffected · git
- 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980 and later · before 98247c8264d2076f81fa114bdfa2c2271953ac7caffected · git
- 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980 and later · before 38ab2a435001a3c4dbeb70a52f5921e1ccd66f55affected · git
- 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980 and later · before f7bf57e94a5d6214b87be08486cb33836fbfa573affected · git
- 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980 and later · before 4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0affected · git
- before 3.16not affected · semver
- 6.6.158 and later · up to and including 6.6.*not affected · semver
- 6.12.111 and later · up to and including 6.12.*not affected · semver
- 6.18.53 and later · up to and including 6.18.*not 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 | from 0 | — |
| 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
Published before and after this one in the same product
- ← EarlierCVE-2026-98024Sep 25, 2026 · s390/ism: folio_put() after error0Monitor
- ← EarlierCVE-2026-98025Sep 25, 2026 · net: usb: cx82310_eth: drop URB after 0xffff reboot sentinel to prevent partial_data heap overflow0Monitor
- Later →CVE-2026-98027Sep 25, 2026 · net: dsa: mv88e6xxx: bound the policy rule dump by the caller's buffer size28Monitor
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 | 37cb9a81600da8250f24e25edc07253b62353cbe | Vendor (CNA) |
| Linux Linux | 38ab2a435001a3c4dbeb70a52f5921e1ccd66f55 | Vendor (CNA) |
| Linux Linux | 4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0 | Vendor (CNA) |
| Linux Linux | 98247c8264d2076f81fa114bdfa2c2271953ac7c | Vendor (CNA) |
| Linux Linux | f7bf57e94a5d6214b87be08486cb33836fbfa573 | Vendor (CNA) |
| azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 | 6.6.158.1-1 · 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).
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)
Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
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 (1)
- Fix✗ → ✓
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References
Show all references (4 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.