Linux Kernel up to 6.18.50/7.2.3 erofs alloc_pages_bulk nrpages buffer overflow

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.5	$5k-$25k	0.84+

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.50/7.2.3. It has been rated as very critical. This affects the function alloc_pages_bulk of the component erofs. The manipulation of the argument nrpages leads to buffer overflow. This vulnerability is traded as CVE-2026-89602. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.50/7.2.3 and classified as very critical. This issue affects the function alloc_pages_bulk of the component erofs. The manipulation of the argument nrpages with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: erofs: skip sufficiently large global buffers when resizing z_erofs_gbuf_nrpages is advanced only after every global buffer has been grown. If a resize fails after some buffers were enlarged, a retry revisits those enlarged buffers. Retrying the same size then returns -ENOMEM because alloc_pages_bulk() has no pages to add and the unchanged return value is treated as a failure. Retrying an intermediate size allocates a temporary pointer array smaller than gbuf->nrpages and copies more existing pointers than the array can hold. Skip buffers that already satisfy the request. Once all remaining buffers have caught up, advancing z_erofs_gbuf_nrpages again describes the guaranteed minimum size across the pool.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-89602 since 09/11/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/12/2026).

Upgrading to version 6.18.51, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch 7267557ce98ccd07faaf3bc86382448950cc4ff6/7f4a89d4f0d6acaf4b756c31de48f2109a257b70/a7d097cf01301c5da37927c8f26123d006f0fd8a is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 6.18.50
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

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

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.51/7.2.4/7.3-rc1
Patch: 7267557ce98ccd07faaf3bc86382448950cc4ff6/7f4a89d4f0d6acaf4b756c31de48f2109a257b70/a7d097cf01301c5da37927c8f26123d006f0fd8a

Timelineinfo

09/11/2026 CVE reserved
09/11/2026 +0 days VulDB entry created
09/12/2026 +0 days Advisory disclosed
09/12/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89602 (🔒)
GCVE (CVE): GCVE-0-2026-89602
GCVE (VulDB): GCVE-100-402899

Entryinfo

Created: 09/12/2026 01:36
Changes: 09/12/2026 01:36 (60)
Complete: 🔍
Cache ID: 216::103

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