Linux kernel Bluetooth ISO BIS binding can drop a parent hold
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 4 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel Bluetooth ISO code in hci_bind_bis() does not take a hold on the parent connection before linking an additional BIS. Unlinking the child then drops the parent's existing hold, which can schedule the parent for disconnection while a socket still uses it. The affected versions are from 6.6.67 before 6.6.158 and from 6.8.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: balance the parent hold in hci_bind_bis() hci_conn_link() takes a lifetime reference to its parent with hci_conn_get(), but only takes an operational hold on the child. hci_conn_unlink() later balances both a hold and a reference on the parent. The SCO and CIS paths pass a parent acquired from a connect helper, so it already has a hold. For an additional BIS, hci_bind_bis() obtains the parent from hci_conn_hash_lookup_big(), which returns a bare pointer. Unlinking the child then drops the parent's existing hold and can schedule it for disconnection while its socket is still using it. Take a hold on the parent before linking it and drop that hold if linking fails. A successful link transfers the hold to hci_conn_unlink().
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade the Linux kernel to 6.6.158, 6.12.112, 6.18.55, 7.2.9 or 7.3, depending on the branch in use. Red Hat rates the flaw Moderate and lists no fix available for Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 and Red Hat OpenShift Container Platform 5.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 6.6.158
- Fix · CNA Linux (Linux) Fixed in 6.6.158, 6.12.112, 6.18.55, 7.2.9, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 5 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98459
- 2026-10-18 Alias added: GHSA-w8fc-m2x5-xcfp
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
References
Other 5
- https://git.kernel.org/stable/c/ff28e6c67143c76ef50c3eac01f2fad411705f71
- https://git.kernel.org/stable/c/03a91cdf6862fb351a74f035ad21e70112438552
- https://git.kernel.org/stable/c/4e49206d9574a4c109480198e73aea34ad0ed7f6
- https://git.kernel.org/stable/c/bbcd723ee7a84bc868142fd57717af88e54e555a
- https://git.kernel.org/stable/c/4c94557dd02569efa6c1072a0439addaef9a5224
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Sources
- CVE-2026-98459 · CVE Program
- CVE-2026-98459 · NVD
- FIRST EPSS
- GHSA-w8fc-m2x5-xcfp · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98459 · Red Hat security data · CC BY 4.0
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