CoreBunch Instatic up to 0.0.14 Render Cache /_instatic/hole u injection

Summaryinfo

A vulnerability was found in CoreBunch Instatic up to 0.0.14. It has been rated as problematic. The affected element is an unknown function of the file /_instatic/hole of the component Render Cache. This manipulation of the argument u causes injection. This vulnerability is registered as CVE-2026-72587. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability classified as problematic was found in CoreBunch Instatic up to 0.0.14. Affected by this vulnerability is an unknown function of the file /_instatic/hole of the component Render Cache. The manipulation of the argument u with an unknown input leads to a injection vulnerability. The CWE definition for the vulnerability is CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. As an impact it is known to affect integrity, and availability. The summary by CVE is:

A cache poisoning vulnerability in CoreBunch/Instatic through 0.0.14 allows an unauthenticated remote attacker to poison the shared process-wide render cache by manipulating the u query parameter of the GET /_instatic/hole/<nodeId> server island endpoint. The originating-page URL supplied in u seeds the route template frame used for rendering, and the result is stored in a shared cache keyed only on nodeId, enabling an attacker to inject a crafted route that causes all subsequent visitors to receive malformed or attacker-controlled fragment content.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-72587 since 08/10/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/10/2026). The attack technique deployed by this issue is T1055 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• CoreBunch

Name

• Instatic

Version

• 0.0.1
• 0.0.2
• 0.0.3
• 0.0.4
• 0.0.5
• 0.0.6
• 0.0.7
• 0.0.8
• 0.0.9
• 0.0.10
• 0.0.11
• 0.0.12
• 0.0.13
• 0.0.14

CPE 2.3info

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CPE 2.2info

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