CVE-2026-55787

7.1High

Published 14 Oct 2026 · NVD status: Deferred · AI triage by gemini-3.8-flash

7.1High

Attack vector: Network
Complexity: High
Privileges needed: Low
User interaction: None
Impact: High impact on confidentiality
Weakness: CWE-918

Impact

Authenticated workflow authors can perform full-read SSRF against loopback, internal networks, or cloud metadata endpoints to steal internal data and credentials. They need valid credentials to execute workflows via the Execution API or guarded outbound request modules.

Root cause

SSRF IP-validation functions fail to unwrap IPv6 transition formats like IPv4-mapped, 6to4, and NAT64 addresses before evaluating them against private ranges.

Affected systems

Flyto2 Core versions prior to 2.26.3

CVSS v3.1 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N

Fix & remediation

Upgrade Flyto2 Core to version 2.26.3 or later. If updating immediately is not possible, block or disable outbound IPv6 routing/transition addresses at the host or network firewall level.

shell

$ pip install --upgrade flyto-core>=2.26.3

AI-suggested. Run it in staging first and check it against the vendor advisory. Why?

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NVD description

Flyto2 Core is an execution kernel for automation and AI-agent workflows. Prior to 2.26.3, validate_url_ssrf and is_private_ip in src/core/utils.py compare resolved addresses only against native private IPv4 and IPv6 ranges and do not unwrap IPv4-mapped, IPv4-compatible, 6to4, or NAT64 transition addresses. An authenticated workflow author can provide a transition-form literal URL through the Execution API POST /v1/execute route, http.get, or sibling guarded outbound-request modules, causing the guard to accept an address whose embedded IPv4 points to loopback, RFC 1918, or cloud metadata services. On a host that routes the selected transition form, the outbound request reaches the internal destination and returns the response body to the workflow caller, enabling read SSRF and disclosure of internal-service data or cloud credentials. This issue is fixed in version 2.26.3.

References

Source: nvd.nist.gov/vuln/detail/CVE-2026-55787