Use-after-free in Linux kernel xen-netback statistics handling
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
- Fixed
No CVSS vector from any source. Fix status from CNA.
Summary
Linux kernel versions before 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, 6.18.62 and 7.3.3 are affected in the xen-netback driver. The driver frees network statistics data without waiting for RCU readers to finish, so queue teardown after a failed frontend connection, for example from illegal Xenstore data set by the guest, can free data that sysfs is still reading. Reading the statistics through sysfs during this phase can then access freed memory.
Written with Claude Haiku 5.5 from the sources below · 2026-11-08
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: xen-netback: Fix UAF when reading statistics data The network statistic data in the driver is protected by RCU. Unfortunately when tearing down the queues after an error during connecting to the frontend (e.g. due to illegal Xenstore data filled in by the guest), the statistic data is being freed without synchronizing the RCU state. In case the data is being read via sysfs in this phase, access to already freed memory or memory being in new use is possible. Fix that by calling synchronize_net() before freeing the queue data. This is XSA-526 / CVE-2026-100080
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | before 5.10.274; before 5.15.225; before 6.1.192; before 6.6.162; before 6.12.116; before 6.18.62; before 7.3.3 | 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, 6.18.62, 7.3.3 | Patch available | CNA |
| Linux | Linux | — | 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, 6.18.62, 7.3.3 | Patch available | CNA |
- Linux VendorLinux Affected before 5.10.274; before 5.15.225; before 6.1.192; before 6.6.162; before 6.12.116; before 6.18.62; before 7.3.3 Fixed in 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, 6.18.62, 7.3.3 Patch available CNA
- Linux VendorLinux Affected — Fixed in 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, 6.18.62, 7.3.3 Patch available CNA
Remediation
Update to a fixed Linux kernel release: 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, 6.18.62 or 7.3.3.
Written with Claude Haiku 5.5 from the sources below · 2026-11-08
- Fix · CNA Linux (Linux) Fixed in 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, 6.18.62, 7.3.3
- Fix · CNA Linux (Linux) Fixed in 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, 6.18.62, 7.3.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 7 products
- Red Hat Enterprise Linux 10
- 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
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-11-06 Threatist record created from CVE-2026-100080
- 2026-11-06 Alias added: GHSA-q39v-hr2r-27c9
- 2026-11-08 Affected versions changed · Red Hat
- 2026-11-08 CVSS score added · Red Hat
References
Other 7
- https://git.kernel.org/stable/c/4223b33be49ee09acb6f1d26beb4a36dd3b8d63a
- https://git.kernel.org/stable/c/ab9cdf1291be551da999510b30216a2886074d7a
- https://git.kernel.org/stable/c/36f858f228e3f955b9336af7f94634747c221518
- https://git.kernel.org/stable/c/89e534265b62c94749639350200b10370564bb3a
- https://git.kernel.org/stable/c/6cd611d2abdd8623a554e14145f82c1cb4e4467a
- https://git.kernel.org/stable/c/37d5a73170579b30e67cc8b19ec69715eea3a6b6
- https://git.kernel.org/stable/c/4867687b6ad28ab84bc0811d8f8f9972e769da02
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Sources
- CVE-2026-100080 · CVE Program
- CVE-2026-100080 · NVD
- FIRST EPSS
- GHSA-q39v-hr2r-27c9 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-100080 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences