CVE-2026-74580Linux Kernel Vulnerability
Linux kernel: vhost: reset the vring metadata cache on vring reconfiguration
Published Aug 21, 2026 · Updated Oct 16, 2026 · Also known as TR-26-0893, UBUNTU-CVE-2026-74580
Key Facts
Patch in the next maintenance window- CVE-2026-74580 is a high-severity vulnerability (CVSS 8.8 v3.1) affecting Azl3 Kernel 6.6.150.1-1 (Microsoft), Linux Kernel, linux-6.12 (debian) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 0.1% probability of exploitation in the next 30 days.
- Fixed versions are available, including bpftool 1:6.1.182-227.379.amzn2023, bpftool 5.15.0-324.217.5.2.el8uek, bpftool 5.15.0-324.217.5.2.el9uek.
- Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
Scores
CVSS v3.1
8.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
0.1%
Higher than 2.0% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
48/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Proof of concept
Public exploit code
3
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Advisories And Exploit References
- advisoryhttps://www.cve.org/CVERecord?id=CVE-2026-74580
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-74580
- advisoryhttps://ubuntu.com/security/CVE-2026-74580
- advisoryRHSA-2026:62568
- advisoryhttps://git.kernel.org/stable/c/3d3c212b70633332ab71672aa2bc6af257d2ec83
- advisoryhttps://git.kernel.org/stable/c/40d2ffb74094cf36edbe05855566a4c58b6ce808
Description
In the Linux kernel, the following vulnerability has been resolved:
vhost: reset the vring metadata cache on vring reconfiguration
vq->meta_iotlb[] caches the vhost_iotlb_map that backs each vring metadata region, and iotlb_access_ok() returns early on a cache hit, taking the hit as proof that the region has already been validated:
if (vhost_vq_meta_fetch(vq, addr, len, type)) return true;
The cache is reset on VHOST_IOTLB_UPDATE and VHOST_IOTLB_INVALIDATE, on device IOTLB (re)initialisation and on vq reset, but not when VHOST_SET_VRING_ADDR replaces vq->desc, vq->avail and vq->used, nor when VHOST_SET_VRING_NUM changes the region sizes.
With a device IOTLB attached both ioctls are accepted while the vq is live, and neither validates the addresses at ioctl time: vq_access_ok() and vq_log_used_access_ok() return true early because the addresses are GIOVAs, deferring validation to prefetch time.
Once the cache has been populated that deferred validation no longer runs -- vq_meta_prefetch() hits the stale entry and returns true -- and vhost_vq_meta_fetch() keeps translating through the old mapping as
map->addr + addr - map->start
for an address the mapping no longer covers. vhost_copy_to_user() and vhost_copy_from_user() consume the result with copy_to_user() and copy_from_user(), which do not check it either, so a subsequent used ring update or descriptor fetch accesses memory outside the region the IOTLB actually maps.
Reset the metadata cache whenever the vring is reconfigured, so the new addresses are pushed back through iotlb_access_ok()'s slow path.
Affected Products
1,207 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Azl3 Kernel 6.6.150.1-1Microsoft | See advisory | n/a |
| Linux KernelLinux | See advisory | 5.10.265 |
| linux-6.12debian | See advisory | 6.12.107-1~deb12u1 |
| Linuxdebian | >= f889491380582b4ba2981cf0b0d7d6a40fb30ab7 | 6.1.187-1 |
| linux-allwinner-5.19ubuntu | See advisory | n/a |
Patched Releases
bpftool
1:6.1.182-227.379.amzn2023, 5.15.0-324.217.5.2.el8uek, 5.15.0-324.217.5.2.el9uek, 5.15.0-325.220.5.el8uek, 5.15.0-325.220.5.el9uek, 6.12.107-1.ph5
bpftool6.12
1:6.12.103-127.188.amzn2023
bpftool6.18
1:6.18.44-99.149.amzn2023
Kernel
0:5.14.0-570.138.1.el9_6, 1:6.1.182-227.379.amzn2023, 4.14.355-284.742.amzn2, 6.6.152.1-1, 5.10.265, 5.15.216, 6.1.183, 6.12.104, 6.18.45, 6.6.152, 7.1.9
kernel-debuginfo-common-aarch64
1:6.1.182-227.379.amzn2023, 4.14.355-284.742.amzn2
kernel-debuginfo-common-x86_64
1:6.1.182-227.379.amzn2023, 4.14.355-284.742.amzn2
kernel-devel
1:6.1.182-227.379.amzn2023, 4.14.355-284.742.amzn2
kernel-headers
1:6.1.182-227.379.amzn2023, 4.14.355-284.742.amzn2
kernel-livepatch-4.14.355-284.742
1.0-0.amzn2
kernel-livepatch-6.1.182-227.379
1:1.0-0.amzn2023
kernel-livepatch-6.12.103-127.188
1:1.0-0.amzn2023
kernel-livepatch-6.18.44-99.149
1:1.0-0.amzn2023
kernel-modules-extra
1:6.1.182-227.379.amzn2023
kernel-modules-extra-common
1:6.1.182-227.379.amzn2023
kernel-tools
1:6.1.182-227.379.amzn2023, 4.14.355-284.742.amzn2
kernel-tools-devel
1:6.1.182-227.379.amzn2023, 4.14.355-284.742.amzn2
kernel-uek
5.15.0-324.217.5.2.el8uek, 5.15.0-324.217.5.2.el9uek, 5.15.0-325.220.5.el8uek, 5.15.0-325.220.5.el9uek, 6.12.0-206.104.3.3.el10uek, 6.12.0-206.104.3.3.el9uek, 6.12.0-207.111.5.1.el10uek, 6.12.0-207.111.5.1.el9uek
kernel-uek-container
5.15.0-324.217.5.2.el8uek, 5.15.0-324.217.5.2.el9uek, 5.15.0-325.220.5.el8uek, 5.15.0-325.220.5.el9uek
kernel-uek-container-debug
5.15.0-324.217.5.2.el8uek, 5.15.0-324.217.5.2.el9uek, 5.15.0-325.220.5.el8uek, 5.15.0-325.220.5.el9uek
kernel-uek-core
5.15.0-324.217.5.2.el8uek, 5.15.0-324.217.5.2.el9uek, 5.15.0-325.220.5.el8uek, 5.15.0-325.220.5.el9uek, 6.12.0-206.104.3.3.el10uek, 6.12.0-206.104.3.3.el9uek, 6.12.0-207.111.5.1.el10uek, 6.12.0-207.111.5.1.el9uek
kernel-uek-debug
5.15.0-324.217.5.2.el8uek, 5.15.0-324.217.5.2.el9uek, 5.15.0-325.220.5.el8uek, 5.15.0-325.220.5.el9uek, 6.12.0-206.104.3.3.el10uek, 6.12.0-206.104.3.3.el9uek, 6.12.0-207.111.5.1.el10uek, 6.12.0-207.111.5.1.el9uek
kernel-uek-debug-core
5.15.0-324.217.5.2.el8uek, 5.15.0-324.217.5.2.el9uek, 5.15.0-325.220.5.el8uek, 5.15.0-325.220.5.el9uek, 6.12.0-206.104.3.3.el10uek, 6.12.0-206.104.3.3.el9uek, 6.12.0-207.111.5.1.el10uek, 6.12.0-207.111.5.1.el9uek
kernel-uek-debug-devel
5.15.0-324.217.5.2.el8uek, 5.15.0-324.217.5.2.el9uek, 5.15.0-325.220.5.el8uek, 5.15.0-325.220.5.el9uek, 6.12.0-206.104.3.3.el10uek, 6.12.0-206.104.3.3.el9uek, 6.12.0-207.111.5.1.el10uek, 6.12.0-207.111.5.1.el9uek
kernel-uek-debug-modules
5.15.0-324.217.5.2.el8uek, 5.15.0-324.217.5.2.el9uek, 5.15.0-325.220.5.el8uek, 5.15.0-325.220.5.el9uek, 6.12.0-206.104.3.3.el10uek, 6.12.0-206.104.3.3.el9uek, 6.12.0-207.111.5.1.el10uek, 6.12.0-207.111.5.1.el9uek
kernel-uek-debug-modules-core
6.12.0-206.104.3.3.el10uek, 6.12.0-206.104.3.3.el9uek, 6.12.0-207.111.5.1.el10uek, 6.12.0-207.111.5.1.el9uek
Timeline
Publicly disclosed
Aug 21, 2026
Last updated
Oct 16, 2026
Weakness Type
- CWE-825 Expired Pointer Dereference
References
- advisorycve.org · CVERecord
- advisorynvd.nist.gov · CVE-2026-74580
- advisoryubuntu.com · CVE-2026-74580
- advisoryRHSA-2026:62568
- advisorygit.kernel.org · 3d3c212
FAQ
Common Questions.
In the Linux kernel, the following vulnerability has been resolved: vhost: reset the vring metadata cache on vring reconfiguration vq->meta_iotlb[] caches the vhost_iotlb_map that backs each vring metadata region, and iotlb_access_ok() returns early on a cache hit, taking the hit as proof that the region has already…
Affected: Azl3 Kernel 6.6.150.1-1 (Microsoft); Linux Kernel; linux-6.12 (debian), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including bpftool 1:6.1.182-227.379.amzn2023, bpftool 5.15.0-324.217.5.2.el8uek, bpftool 5.15.0-324.217.5.2.el9uek.
Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
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