CVE-2026-72587

Instatic - Cache Poisoning via Unauthenticated Server Island Endpoint

Published Aug 10, 2026 CVSS 3.1 · 6.1 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
References
History
Type Values Removed Values Added
First Time appeared Corebunch
Corebunch instatic
Vendors & Products Corebunch
Corebunch instatic
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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. 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.
Type Values Removed Values Added
Description 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.
Title Instatic - Cache Poisoning via Unauthenticated Server Island Endpoint
Weaknesses CWE-444
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
TuranSec
Published
Updated
Aug 10, 2026, 1:21 PM
Reserved
Aug 10, 2026, 10:32 AM
Status
Deferred
Published
Aug 10, 2026, 11:17 AM
Modified
Oct 24, 2026, 3:10 PM