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Soft Serve is vulnerable to SSRF through its Webhooks

Critical severity GitHub Reviewed Published Nov 10, 2025 in charmbracelet/soft-serve • Updated Nov 15, 2025

Package

gomod github.com/charmbracelet/soft-serve (Go)

Affected versions

< 0.11.1

Patched versions

0.11.1

Description

SUMMARY

We have identified and verified an SSRF vulnerability where webhook URLs are not validated, allowing repository administrators to create webhooks targeting internal services, private networks, and cloud metadata endpoints.

AFFECTED COMPONENTS (VERIFIED)

  1. Webhook Creation (pkg/ssh/cmd/webhooks.go:125)
  2. Backend CreateWebhook (pkg/backend/webhooks.go:17)
  3. Backend UpdateWebhook (pkg/backend/webhooks.go:122)
  4. Webhook Delivery (pkg/webhook/webhook.go:97)

IMPACT

This vulnerability allows repository administrators to perform SSRF attacks, potentially enabling:

a) Cloud Metadata Theft - Access AWS/Azure/GCP credentials via 169.254.169.254
b) Internal Network Access - Target localhost and private networks (10.x, 192.168.x, 172.16.x)
c) Port Scanning - Enumerate internal services via response codes and timing
d) Data Exfiltration - Full HTTP responses stored in webhook delivery logs
e) Internal API Access - Call internal admin panels and Kubernetes endpoints

PROOF OF CONCEPT

Simple example demonstrating localhost access:

ssh localhost webhook create my-repo http://127.0.0.1:8080/internal \
    --events push --active

then push to trigger.

References

@caarlos0 caarlos0 published to charmbracelet/soft-serve Nov 10, 2025
Published to the GitHub Advisory Database Nov 10, 2025
Reviewed Nov 10, 2025
Published by the National Vulnerability Database Nov 10, 2025
Last updated Nov 15, 2025

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(26th percentile)

Weaknesses

Server-Side Request Forgery (SSRF)

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Learn more on MITRE.

CVE ID

CVE-2025-64522

GHSA ID

GHSA-vwq2-jx9q-9h9f

Source code

Credits

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