Linux Kernel up to 6.12.109/6.18.50/7.2.4 powerpc/kexec_file __merge_memory_ranges memory corruption

CVSS Meta Temp Score
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3.3$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.109/6.18.50/7.2.4. It has been declared as problematic. This impacts the function __merge_memory_ranges of the component powerpc/kexec_file. The manipulation results in memory corruption. This vulnerability is known as CVE-2026-89962. Attacking locally is a requirement. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 6.12.109/6.18.50/7.2.4. Affected is the function __merge_memory_ranges of the component powerpc/kexec_file. The manipulation with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: powerpc/kexec_file: Prevent kexec range truncation Sashiko AI review pointed out the following issue. The __merge_memory_ranges() function incorrectly handles overlapping memory ranges when merging them. Although sort_memory_ranges() sorts all ranges by their start address in ascending order beforehand, the merge logic remains defective in two ways: 1. It compares the current range's start against the previous element (i-1) instead of the running target index (idx) 2. It unconditionally overwrites 'ranges[idx].end' with 'ranges[i].end'. This logic flaw leads to critical memory truncation when a larger memory range completely subsumes subsequent smaller ranges. For example, consider a sorted input array with three ranges: Range A (idx=0): [0x1000 - 0x9000] Range B (i=1): [0x2000 - 0x5000] (completely inside Range A) Range C (i=2): [0x6000 - 0x8000] (completely inside Range A) 1. When i=1 (Range B): ranges[1].start (0x2000) <= ranges[0].end + 1 (0x9001) is TRUE. The code executes: ranges[0].end = ranges[1].end, which erroneously shrinks Range A's end from 0x9000 down to 0x5000. 2. When i=2 (Range C): ranges[2].start (0x6000) <= ranges[1].end + 1 (0x5001) is FALSE. The code falls into the else block, creating a broken new range. As a result, valid memory fragments [0x5001 - 0x5fff] and [0x8001 - 0x9000] are completely lost from the kexec exclude lists, potentially allowing the crash kernel to overwrite active memory, causing data corruption or crashes. Fix this by ensuring the start of the current range is compared against the end of the active merged range (idx), and use max() to safely prevent the outer boundary from being truncated.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-89962 since 09/11/2026. The exploitability is told to be easy. Local access is required to approach this attack. The exploitation requires an enhanced level of successful authentication. Technical details are known, but there is no available exploit.

Upgrading to version 6.12.110, 6.18.51, 7.2.5 or 7.3-rc1 eliminates this vulnerability. Applying the patch 9ef63622e6cee588ea4b763a6afc87065254b36a/da88a2a2119e4fd0e8919a7a2448682f574e1545/c4cb547f26d9b73b489c5278d0c8db837c5a174f/fa40f9dbdd4af53e7445d9135b5b207eb8adf372 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.4
VulDB Meta Temp Score: 3.3

VulDB Base Score: 3.4
VulDB Temp Score: 3.3
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: Memory corruption
CWE: CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
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 6.12.110/6.18.51/7.2.5/7.3-rc1
Patch: 9ef63622e6cee588ea4b763a6afc87065254b36a/da88a2a2119e4fd0e8919a7a2448682f574e1545/c4cb547f26d9b73b489c5278d0c8db837c5a174f/fa40f9dbdd4af53e7445d9135b5b207eb8adf372

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89962 (🔒)
GCVE (CVE): GCVE-0-2026-89962
GCVE (VulDB): GCVE-100-405810

Entryinfo

Created: 09/16/2026 15:06
Changes: 09/16/2026 15:06 (59)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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