Linux Kernel up to 6.18.54/7.2.8 parisc wb_workfn stack-based 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	1.95

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.18.54/7.2.8. The impacted element is the function wb_workfn of the component parisc. Performing a manipulation results in stack-based overflow. This vulnerability is known as CVE-2026-98917. Remote exploitation of the attack is possible. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.18.54/7.2.8. This affects the function wb_workfn of the component parisc. The manipulation with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: parisc: Increase kernel stack size to 32kb For 64-bit Linux kernels, increase the default kernel stack size (THREAD_SIZE_ORDER) to 32 kB, in order to avoid kernel crashes which have been triggered recently when building the debian vtk9 package with gcc 17: stackcheck: kworker/u128:0 will most likely overflow kernel stack (sp:179a83af0, stk bottom-top:179a80000-179a84000) Kernel panic - not syncing: low stack detected by irq handler - check messages CPU: 2 UID: 0 PID: 30760 Comm: kworker/u128:0 Tainted: G W 6.18.46-dirty #1 NONE Tainted: [W]=WARN Hardware name: 9000/800/rp3440 Workqueue: writeback wb_workfn (flush-259:0) Backtrace: [<000000004022f050>] show_stack+0x70/0x90 [<000000004022378c>] dump_stack_lvl+0x124/0x190 [<000000004022382c>] dump_stack+0x34/0x48 [<000000004020212c>] vpanic+0x204/0x648 [<00000000402025c4>] panic+0x54/0x58 [<0000000040232230>] do_cpu_irq_mask+0x3f8/0x440 [<0000000040227070>] intr_return+0x0/0xc

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-98917 since 09/25/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/23/2026).

Upgrading to version 6.18.55 or 7.2.9 eliminates this vulnerability. Applying the patch 5023c70853ad9829c53d8e9def5ee969b4e1b931/db45f02b7a5f753efc9003f616dfb5ee4cb6d077/94b7e3a7e871ae27d4935c76959dfc61829f27f9 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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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
• 6.18.51
• 6.18.52
• 6.18.53
• 6.18.54
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.2.7
• 7.2.8

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: Stack-based overflow
CWE: CWE-121 / 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 6.18.55/7.2.9
Patch: 5023c70853ad9829c53d8e9def5ee969b4e1b931/db45f02b7a5f753efc9003f616dfb5ee4cb6d077/94b7e3a7e871ae27d4935c76959dfc61829f27f9

Timelineinfo

09/25/2026 CVE reserved
10/23/2026 +28 days Advisory disclosed
10/23/2026 +0 days VulDB entry created
10/23/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98917 (🔒)
GCVE (CVE): GCVE-0-2026-98917
GCVE (VulDB): GCVE-100-425685

Entryinfo

Created: 10/23/2026 14:39
Changes: 10/23/2026 14:39 (59)
Complete: 🔍
Cache ID: 216::103

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