Description
Compliance-trestle (Trestle) is a tooling platform for managing compliance as code. In versions before 3.12.4 and versions 4.0.0 through 4.0.3, the URLSecurityValidator that guards trestle's remote-fetch paths against server-side request forgery can be bypassed to reach loopback, link-local, cloud-metadata, and internal network endpoints it was designed to block. The blocklist does not canonicalize IPv4-mapped IPv6 literals such as [::ffff:169.254.169.254], which resolve to IPv6Address objects that never match the blocked IPv4 ranges, and it does not block the unspecified address 0.0.0.0, which routes to local services on Linux and inside containers. An attacker who can supply or influence an OSCAL artifact that trestle fetches, such as a malicious profile whose imports reference one of these bypass URLs, can cause the HTTPSFetcher and SFTPFetcher paths to contact cloud instance-metadata services, loopback interfaces, or internal hosts. This issue is fixed in versions 3.12.4 and 4.1.0.
Published: 2026-08-25
Score: 8.6 High
EPSS: < 1% Very Low
KEV: No
Impact: Server‑Side Request Forgery (SSRF) to internal and metadata endpoints.
Action: Apply Patches
AI Analysis

Impact

The vulnerability is a server‑side request forgery in the URLSecurityValidator of Compliance‑Trestle that allows bypassing the allowlist by using IPv4‑mapped IPv6 literals such as [::ffff:169.254.169.254] and the unspecified IPv4 address 0.0.0.0. This bypass permits the tool to fetch resources from loopback, link‑local, cloud instance‑metadata, and other internal network endpoints that were intended to be blocked, potentially exposing sensitive internal services and data.

Affected Systems

The affected product is oscal‑compass compliance‑trestle (Trestle) versions prior to 3.12.4 and versions 4.0.0 through 4.0.3. The fix is available in 3.12.4 and 4.1.0.

Risk and Exploitability

With a CVSS score of 8.6 the vulnerability is classified as high severity, and although the EPSS score is available but indicates a very low probability (< 1%) it remains a serious risk. The attack requires an attacker to supply or influence an OSCAL artifact that Trestle will fetch; once this is achieved the attacker can cause Trestle to contact cloud metadata services, loopback interfaces, or internal hosts. The vulnerability is not listed in CISA’s KEV catalog, but the potential impact on internal network reconnaissance or data exfiltration warrants immediate attention.

Generated by OpenCVE AI on August 28, 2026 at 18:31 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade compliance‑trestle to version 3.12.4 or later 4.1.0, which contains the URLSecurityValidator fix.
  • If an upgrade cannot be performed immediately, limit the network connectivity of the Trestle process to block 127.0.0.1, 0.0.0.0, 169.254.0.0/16, and other internal address ranges using firewall or container network policies.
  • Ensure that any OSCAL artifact imported by Trestle originates from a trusted source and that its URLs are subjected to strict whitelist validation before fetching, following best practices for mitigating SSRF.
  • Monitor outbound connections from Trestle for unexpected requests to internal or metadata endpoints.

Generated by OpenCVE AI on August 28, 2026 at 18:31 UTC.

Tracking

Sign in to view the affected projects.

Advisories
Source ID Title
Github GHSA Github GHSA GHSA-h47f-gmjp-m7rr compliance-trestle has an URLSecurityValidator SSRF allowlist bypass via IPv4-mapped IPv6 and 0.0.0.0
History

Thu, 27 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1289
References
Metrics threat_severity

None

 cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'}

threat_severity

Important

Wed, 26 Aug 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Wed, 26 Aug 2026 02:00:00 +0000

Type Values Removed Values Added
First Time appeared Oscal-compass
Oscal-compass compliance-trestle
Vendors & Products Oscal-compass
Oscal-compass compliance-trestle

Tue, 25 Aug 2026 23:30:00 +0000

Type Values Removed Values Added
Description Compliance-trestle (Trestle) is a tooling platform for managing compliance as code. In versions before 3.12.4 and versions 4.0.0 through 4.0.3, the URLSecurityValidator that guards trestle's remote-fetch paths against server-side request forgery can be bypassed to reach loopback, link-local, cloud-metadata, and internal network endpoints it was designed to block. The blocklist does not canonicalize IPv4-mapped IPv6 literals such as [::ffff:169.254.169.254], which resolve to IPv6Address objects that never match the blocked IPv4 ranges, and it does not block the unspecified address 0.0.0.0, which routes to local services on Linux and inside containers. An attacker who can supply or influence an OSCAL artifact that trestle fetches, such as a malicious profile whose imports reference one of these bypass URLs, can cause the HTTPSFetcher and SFTPFetcher paths to contact cloud instance-metadata services, loopback interfaces, or internal hosts. This issue is fixed in versions 3.12.4 and 4.1.0.
Title Trestle URLSecurityValidator SSRF allowlist bypass via IPv4-mapped IPv6 and 0.0.0.0
Weaknesses CWE-184
CWE-918
References
Metrics cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

Subscriptions

Oscal-compass Compliance-trestle
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-26T14:23:57.204Z

Reserved: 2026-06-08T17:13:43.065Z

Link: CVE-2026-52776

cve-icon Vulnrichment

Updated: 2026-08-26T14:23:53.744Z

cve-icon NVD

Status : Deferred

Published: 2026-08-26T05:18:10.880

Modified: 2026-09-09T21:09:13.080

Link: CVE-2026-52776

cve-icon Redhat

Severity : Important

Publid Date: 2026-08-25T23:12:24Z

Links: CVE-2026-52776 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-28T18:45:03Z

Weaknesses
  • CWE-1289

    Improper Validation of Unsafe Equivalence in Input

  • CWE-184

    Incomplete List of Disallowed Inputs

  • CWE-918

    Server-Side Request Forgery (SSRF)