SSRF in Bentoml
CVE-2026-78205
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (33.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/bentoml/BentoML/issues/5644 (issue-tracking)
- github.com/bentoml/BentoML (product)
- github.com/bentoml/BentoML/blob/v1.4.39/src/bentoml/_internal/utils/uri.py (technical-description)
- www.vulncheck.com/advisories/bentoml-through-server-side-request-forgery-via-un… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-78205?
- CVE-2026-78205 is a medium-severity vulnerability in Bentoml, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.8/10. Published 2026-08-24.
- How severe is CVE-2026-78205?
- Medium severity. CVSS v3 base score is 5.8 out of 10.