Vulnerability · Published Aug 24, 2026 · Assigned by VulnCheck

CVE-2026-78205BentoML 1.4.19 through 1.4.39 Server-Side Request Forgery via Unfiltered RFC 6598 Shared Address Space

Medium 5.8

In plain English

A medium-severity server-side request forgery in BentoML from bentoml. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities).

Severity (CVSS 3.1)5.8Medium

Exploit odds (30 days)0.4%top 64.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

BentoML's outbound connection safeguard (make_safe_connect in _internal/utils/uri.py) blocks private, loopback, and link-local IP addresses but fails to reject the RFC 6598 shared address space (100.64.0.0/10, CGNAT). In versions 1.4.19 through 1.4.39, an unauthenticated attacker can supply URLs pointing to that range via multipart file handling (MultipartSerde.ensure_file) or JSON request parsing (JSONSerde.parse_request), causing the server to make outbound requests to internal hosts on CGNAT networks (Server-Side Request Forgery). This is an incomplete fix for CVE-2025-54381.

Affected products (as reported)

Vendor	Product	Versions
bentoml	BentoML	1.4.19 – through 1.4.39

Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

References

GitHub Issue #5644 issue-tracking
https://github.com/bentoml/BentoML product
https://github.com/bentoml/BentoML/blob/v1.4.39/src/bentoml/_internal/utils/uri.py#L89-L96 technical-description
VulnCheck Advisory: BentoML 1.4.19 through 1.4.39 Server-Side Request Forgery via Unfiltered RFC 6598 Shared Address Space third-party-advisory