heymrun Heym up to 0.0.90 SSRF Guard ssrf_guard.py _load_image_bytes/_is_public_address userInput server-side request forgery

Summaryinfo

A vulnerability classified as problematic has been found in heymrun Heym up to 0.0.90. The affected element is the function _load_image_bytes/_is_public_address of the file app/services/ssrf_guard.py of the component SSRF Guard. The manipulation of the argument userInput leads to server-side request forgery. This vulnerability is documented as CVE-2026-100863. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in heymrun Heym up to 0.0.90 and classified as problematic. This issue affects the function _load_image_bytes/_is_public_address of the file app/services/ssrf_guard.py of the component SSRF Guard. The manipulation of the argument userInput with an unknown input leads to a server-side request forgery vulnerability. Using CWE to declare the problem leads to CWE-918. 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. Impacted is confidentiality. The summary by CVE is:

Heym versions 0.0.90 and earlier contain two server-side request forgery (SSRF) egress gaps, both remediated in app/services/ssrf_guard.py in 0.0.91. First, the LLM image-edit input loader (_load_image_bytes) fetched caller-controlled HTTP/HTTPS URLs with a bare httpx.get, applying only a scheme check and bypassing the egress-pinning HTTP client; because the workflow DSL supports "imageInput": "$userInput.body.imageUrl", a webhook or API caller can choose the fetch target when a workflow author uses that expression, allowing requests to loopback, RFC1918, and cloud metadata endpoints. Second, _is_public_address unwrapped only IPv4-mapped IPv6 addresses, so IPv6 transition forms — the NAT64 well-known prefix 64:ff9b::/96, deprecated IPv4-compatible ::x.x.x.x addresses, and 6to4 (2002::/16, classified as globally routable by Python 3.11.0 through 3.11.9) — could carry loopback, RFC1918, link-local, or cloud-metadata IPv4 destinations past both the initial URL validation and the dial-time IP pin. Version 0.0.91 routes the image loader through guard_http_url and the guarded client, evaluates NAT64 and IPv4-compatible addresses by their embedded IPv4 address, and refuses 64:ff9b:1::/48, 6to4, and Teredo (2001::/32) outright.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-100863 since 09/27/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available.

Upgrading to version 0.0.91 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• heymrun

Name

• Heym

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
• 0.0.15
• 0.0.16
• 0.0.17
• 0.0.18
• 0.0.19
• 0.0.20
• 0.0.21
• 0.0.22
• 0.0.23
• 0.0.24
• 0.0.25
• 0.0.26
• 0.0.27
• 0.0.28
• 0.0.29
• 0.0.30
• 0.0.31
• 0.0.32
• 0.0.33
• 0.0.34
• 0.0.35
• 0.0.36
• 0.0.37
• 0.0.38
• 0.0.39
• 0.0.40
• 0.0.41
• 0.0.42
• 0.0.43
• 0.0.44
• 0.0.45
• 0.0.46
• 0.0.47
• 0.0.48
• 0.0.49
• 0.0.50
• 0.0.51
• 0.0.52
• 0.0.53
• 0.0.54
• 0.0.55
• 0.0.56
• 0.0.57
• 0.0.58
• 0.0.59
• 0.0.60
• 0.0.61
• 0.0.62
• 0.0.63
• 0.0.64
• 0.0.65
• 0.0.66
• 0.0.67
• 0.0.68
• 0.0.69
• 0.0.70
• 0.0.71
• 0.0.72
• 0.0.73
• 0.0.74
• 0.0.75
• 0.0.76
• 0.0.77
• 0.0.78
• 0.0.79
• 0.0.80
• 0.0.81
• 0.0.82
• 0.0.83
• 0.0.84
• 0.0.85
• 0.0.86
• 0.0.87
• 0.0.88
• 0.0.89
• 0.0.90

Website

• Product: https://github.com/heymrun/heym/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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