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NVD / CVE Program· CNA Linux

CVE-2026-74580: vhost: reset the vring metadata cache on vring reconfiguration

Noroxi assessment

Priority: Monitor (action score 35/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.40% (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 13fa6f32a56a386a82bd7451644c494beed034af, 5224bd37e37d36076a550d99b2aebba33939fd95, 54617e9119be2eb728ecdd8d977b99c99d4c498a; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 13fa6f32a56a386a82bd7451644c494beed034af, 5224bd37e37d36076a550d99b2aebba33939fd95, 54617e9119be2eb728ecdd8d977b99c99d4c498a; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1 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: 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.

HighCVSS 8.8 · v3.1—Proof of concept Fix available
Published
Aug 21, 2026
Updated
Oct 29, 2026
EPSS
0.4% · 35th percentile
CWE
—

Report tools

JSON

Action score

35

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.8
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.

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  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

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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.

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Affected 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

    • 4.11affected
    • f889491380582b4ba2981cf0b0d7d6a40fb30ab7 and later · before 5224bd37e37d36076a550d99b2aebba33939fd95affected · git
    • f889491380582b4ba2981cf0b0d7d6a40fb30ab7 and later · before 54617e9119be2eb728ecdd8d977b99c99d4c498aaffected · git
    • f889491380582b4ba2981cf0b0d7d6a40fb30ab7 and later · before 13fa6f32a56a386a82bd7451644c494beed034afaffected · git
    • f889491380582b4ba2981cf0b0d7d6a40fb30ab7 and later · before cf363a7a02ce132ef1f58084fdb13e1a3b7da7e7affected · git
    • f889491380582b4ba2981cf0b0d7d6a40fb30ab7 and later · before 6fa3e9b1fe856259555a7e22f3f3082e7827fd9baffected · git
    • f889491380582b4ba2981cf0b0d7d6a40fb30ab7 and later · before f1e21108e3ddfcce62f6cad4ebd7b5674543c9e6affected · git
    • f889491380582b4ba2981cf0b0d7d6a40fb30ab7 and later · before b70ebe0bba254e093dd5fd4c0c170941ce83eb85affected · git
    • f889491380582b4ba2981cf0b0d7d6a40fb30ab7 and later · before de845981da67a6b049080c87e605130b0c30adc5affected · git
    • before 4.11not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.156.1.el8_104.18.0-553.156.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.156.1.rt7.497.el8_104.18.0-553.156.1.rt7.497.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.156.1.rt7.497.el8_104.18.0-553.156.1.rt7.497.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.156.1.rt7.497.el8_104.18.0-553.156.1.rt7.497.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.156.1.rt7.497.el8_104.18.0-553.156.1.rt7.497.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.156.1.rt7.497.el8_104.18.0-553.156.1.rt7.497.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.156.1.rt7.497.el8_104.18.0-553.156.1.rt7.497.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.156.1.rt7.497.el8_104.18.0-553.156.1.rt7.497.el8_10
AlmaLinux:8kernel-rt-develbefore 4.18.0-553.156.1.rt7.497.el8_104.18.0-553.156.1.rt7.497.el8_10
AlmaLinux:8kernel-rt-modulesbefore 4.18.0-553.156.1.rt7.497.el8_104.18.0-553.156.1.rt7.497.el8_10

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-74578Aug 16, 2026 · crypto: algif_skcipher - force synchronous processing on trees without ctx->state
    28Monitor
  • ← EarlierCVE-2026-74579Aug 17, 2026 · netfilter: nft_payload: fix mask build for partial field offload
    28Monitor
  • Later →CVE-2026-74581Aug 21, 2026 · net: ipv6: clear suppressed fib6 rule result
    39Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux13fa6f32a56a386a82bd7451644c494beed034afVendor (CNA)
Linux Linux5224bd37e37d36076a550d99b2aebba33939fd95Vendor (CNA)
Linux Linux54617e9119be2eb728ecdd8d977b99c99d4c498aVendor (CNA)
Linux Linux6fa3e9b1fe856259555a7e22f3f3082e7827fd9bVendor (CNA)
Linux Linuxb70ebe0bba254e093dd5fd4c0c170941ce83eb85Vendor (CNA)
Linux Linuxcf363a7a02ce132ef1f58084fdb13e1a3b7da7e7Vendor (CNA)
Linux Linuxde845981da67a6b049080c87e605130b0c30adc5Vendor (CNA)
Linux Linuxf1e21108e3ddfcce62f6cad4ebd7b5674543c9e6Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.06.6.152.1-1 · Release NotesMicrosoft (MSRC)
almalinux:bpftool4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.156.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.187-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.107-1~deb12u1 · Debian:12Package registry (OSV)
red hat:bpftool0:4.18.0-553.156.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-553.156.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-553.156.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-570.138.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-570.138.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-570.138.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-570.138.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)

+17

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×4

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02026-10-14
Proof-of-concept repository on GitHubstars:22026-10-14
Proof-of-concept repository on GitHubstars:12026-10-17
Proof-of-concept repository on GitHubstars:22026-10-25

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.

  1. Published
  2. First PoC+53 d
  3. TodayNov 10, 2026+81 d
EPSS, last 120 days

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 researchers

Finders, 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.

All national notices →

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

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
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:C/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

  1. SSVC exploitationnone → poc
  2. SSVC exploitation— → none
  3. Exploit maturitynone → poc
  4. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (9 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records