6.9
MEDIUM CVSS 4.0
CVE-2026-78205
BentoML 1.4.19 through 1.4.39 Server-Side Request Forgery via Unfiltered RFC 6598 Shared Address Space
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.

INFO

Published Date :

Aug. 24, 2026, 1:16 a.m.

Last Modified :

Aug. 24, 2026, 1:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-78205 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update BentoML to patch Server-Side Request Forgery vulnerability related to CGNAT IP addresses.
  • Update BentoML to a version addressing the CGNAT IP issue.
  • Validate outbound connection controls.
  • Review and restrict handling of external URLs.
  • Monitor network traffic for suspicious requests.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-78205 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-78205 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-78205 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-78205 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 24, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'bentoml', 'product': 'BentoML', 'versions': [{'status': 'affected', 'version': '1.4.19', 'versionType': 'semver', 'lessThanOrEqual': '1.4.39'}], 'packageURL': 'pkg:pypi/bentoml', 'defaultStatus': 'unaffected'}]
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
    Added CWE CWE-918
    Added Reference https://github.com/bentoml/BentoML
    Added Reference https://github.com/bentoml/BentoML/blob/v1.4.39/src/bentoml/_internal/utils/uri.py#L89-L96
    Added Reference https://github.com/bentoml/BentoML/issues/5644
    Added Reference https://www.vulncheck.com/advisories/bentoml-through-server-side-request-forgery-via-unfiltered-rfc-6598-shared-address-space
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.