Linux Kernel up to 7.1.8 vhost vq_meta_prefetch out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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8.7$0-$5k0.43

Summaryinfo

A vulnerability has been found in Linux Kernel up to 7.1.8 and classified as very critical. This issue affects the function vq_meta_prefetch of the component vhost. The manipulation leads to out-of-bounds. This vulnerability is referenced as CVE-2026-74580. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.1.8. It has been rated as very critical. This issue affects the function vq_meta_prefetch of the component vhost. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-74580 since 08/15/2026. The exploitation is known to be easy. The attack may be initiated remotely. The exploitation requires an enhanced level of successful authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/21/2026).

Upgrading to version 5.10.265, 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch 5224bd37e37d36076a550d99b2aebba33939fd95/54617e9119be2eb728ecdd8d977b99c99d4c498a/13fa6f32a56a386a82bd7451644c494beed034af/cf363a7a02ce132ef1f58084fdb13e1a3b7da7e7/6fa3e9b1fe856259555a7e22f3f3082e7827fd9b/f1e21108e3ddfcce62f6cad4ebd7b5674543c9e6/b70ebe0bba254e093dd5fd4c0c170941ce83eb85/de845981da67a6b049080c87e605130b0c30adc5 is able to eliminate this problem.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.1
VulDB Meta Temp Score: 8.7

VulDB Base Score: 9.1
VulDB Temp Score: 8.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.265/5.15.216/6.1.183/6.6.152/6.12.104/6.18.45/7.1.9
Patch: 5224bd37e37d36076a550d99b2aebba33939fd95/54617e9119be2eb728ecdd8d977b99c99d4c498a/13fa6f32a56a386a82bd7451644c494beed034af/cf363a7a02ce132ef1f58084fdb13e1a3b7da7e7/6fa3e9b1fe856259555a7e22f3f3082e7827fd9b/f1e21108e3ddfcce62f6cad4ebd7b5674543c9e6/b70ebe0bba254e093dd5fd4c0c170941ce83eb85/de845981da67a6b049080c87e605130b0c30adc5

Timelineinfo

08/15/2026 CVE reserved
08/21/2026 +6 days Advisory disclosed
08/21/2026 +0 days VulDB entry created
08/21/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74580 (🔒)
GCVE (CVE): GCVE-0-2026-74580
GCVE (VulDB): GCVE-100-394145

Entryinfo

Created: 08/21/2026 18:57
Changes: 08/21/2026 18:57 (59)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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