Linux Kernel up to 6.12.111/6.18.53/7.2.7/7.3-rc3 swiotlb swiotlb_bounce out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.91-

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.12.111/6.18.53/7.2.7/7.3-rc3. This issue affects the function swiotlb_bounce of the component swiotlb. Executing a manipulation can lead to out-of-bounds write. This vulnerability is registered as CVE-2026-98254. It is possible to launch the attack remotely. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.12.111/6.18.53/7.2.7/7.3-rc3 and classified as very critical. This vulnerability affects the function swiotlb_bounce of the component swiotlb. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: swiotlb: use the adjusted address for the highmem page lookup swiotlb_bounce() reads the page frame number from the slot's recorded orig_addr, then advances orig_addr by tlb_offset to reach the address the caller asked about. The highmem branch mixes the two: the offset within the page comes from the adjusted address, the page from the value before it. Once the adjustment crosses a page boundary the pair no longer describes one location, and the whole copy lands one page below the intended one for a positive tlb_offset, one above for a negative one. DMA_FROM_DEVICE writes the device data over the wrong page and leaves the intended one stale, DMA_TO_DEVICE feeds the device from a page the mapping may not cover. Partial syncs through dma_sync_single_range_for_*() are what make tlb_offset non-zero. The branch test is picked the same way, so a slot recorded in lowmem can be adjusted into highmem and the lowmem path then hands a highmem address to phys_to_virt(). Take both from orig_addr once it is final and keep pfn in the branch that uses it. PhysHighMem() asks the question straight from the address, as dma-debug already does.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-98254 since 09/25/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 10/06/2026).

Upgrading to version 6.12.112, 6.18.54, 7.2.8 or 7.3-rc4 eliminates this vulnerability. Applying the patch 6e53b4d6afbde626255805d438cabb1cac482445/aa4709813b29db89f2307f968db5d24925dcdeb1/b7d7914a9ae3097e63d113007e4fb44d33d515b1 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
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 write
CWE: CWE-787 / 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 6.12.112/6.18.54/7.2.8/7.3-rc4
Patch: 6e53b4d6afbde626255805d438cabb1cac482445/aa4709813b29db89f2307f968db5d24925dcdeb1/b7d7914a9ae3097e63d113007e4fb44d33d515b1

Timelineinfo

09/25/2026 CVE reserved
10/06/2026 +11 days Advisory disclosed
10/06/2026 +0 days VulDB entry created
10/06/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98254 (🔒)
GCVE (CVE): GCVE-0-2026-98254
GCVE (VulDB): GCVE-100-414220

Entryinfo

Created: 10/06/2026 13:47
Changes: 10/06/2026 13:47 (59)
Complete: 🔍
Cache ID: 216::103

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