CVE-2026-63004: Unleash: Addon webhook URL is dialed server-side with no internal-address filtering, enabling SSRF to internal services / cloud metadata and exfiltration of configured request headers

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-21 · updated 2026-10-14
Weakness: CWE-918

Description

Unleash is an open-source feature management platform. Prior to 7.5.2, 7.6.5, and 8.0.2, the addon and integration subsystem passes the operator-controlled parameters.url value from src/lib/addons/webhook.ts and the Slack, Microsoft Teams, Datadog, and New Relic integrations to Addon.fetchRetry in src/lib/addons/addon.ts without restricting loopback, link-local, private, or cloud metadata addresses. An authenticated actor with the root CREATE_ADDON or UPDATE_ADDON permission can cause the server to send requests from inside its network boundary, use integration event status as a blind probing oracle, forward Authorization, customHeaders, or DD-API-KEY values to an attacker-observed host, and deliver the feature-event JSON body to internal services. This issue is fixed in versions 7.5.2, 7.6.5, and 8.0.2.

Affected products

unleash: before 7.5.2; from 7.6.0, < 7.6.5; from 8.0.0, < 8.0.2

References

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