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NVD / CVE Program· CNA GitHub_M

CVE-2025-27520: BentoML Allows Remote Code Execution (RCE) via Insecure Deserialization

Noroxi assessment

Priority: This week (action score 60/100)

  • A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
  • A ready-made attack tool exists and the flaw can be exploited over the network without an account, so priority is at least “This week”.
  • Probability of exploitation in the next 30 days: 40.6% (FIRST EPSS); higher than 98.6% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: bentoml BentoML 1.4.3.

Don’t wait for the next maintenance window. Upgrade to bentoml BentoML 1.4.3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

BentoML is a Python library for building online serving systems optimized for AI apps and model inference. A Remote Code Execution (RCE) vulnerability caused by insecure deserialization has been identified in the latest version (v1.4.2) of BentoML. It allows any unauthenticated user to execute arbitrary code on the server. It exists an unsafe code segment in serde.py. This vulnerability is fixed in 1.4.3.

CriticalCVSS 9.8 · v3.1—Weaponized Fix available
Published
Apr 4, 2025
Updated
Jun 17, 2026
EPSS
40.6% · 98th percentile

Report tools

JSON

Action score

60

This week

Don’t wait for the next maintenance window.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
12 / 30 · 40.6%
Ready-made attack tool
9 / 60 · floor: at least 60

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
9.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-27520

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
bentomlbentoml

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • bentoml bentoml1.3.4 and later · up to 1.4.2 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • bentoml BentoML

    • >= 1.3.4, < 1.4.3affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
PyPIbentomlfrom 1.3.4 · before 1.4.31.4.3

Same product

bentoml: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-32375Insecure Deserialization leads to RCE in BentoML's runner server
    60This week
  • CVE-2025-54381BentoML is Vulnerable to an SSRF Attack Through File Upload Processing
    44Plan
  • CVE-2026-35044BentoML has a Server-Side Template Injection via unsandboxed Jinja2 Environment in Dockerfile generation
    38Monitor

Published before and after this one in the same product

  • Later →CVE-2026-24123Jan 26, 2026 · BentoML has a Path Traversal via Bentofile Configuration
    26Monitor
  • Later →CVE-2026-27905Mar 3, 2026 · BentoML has an Arbitrary File Write via Symlink Path Traversal in Tar Extraction
    34Monitor
  • Later →CVE-2026-33744Mar 27, 2026 · BentoML has Dockerfile Command Injection via system_packages in bentofile.yaml
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
bentoml BentoML1.4.3 · descriptionVendor (CNA)
PyPI:bentoml1.4.3Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Proof-of-concept repository on GitHub ×3

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Metasploit moduleexploit/linux/http/bentoml_rce_cve_2025_27520BentoML RCEexploit2025-04-04
Proof-of-concept repository on GitHubstars:02025-09-22
Proof-of-concept repository on GitHubstars:02026-02-04
Proof-of-concept repository on GitHubstars:02026-07-24

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Metasploitsame day
  2. Published
  3. First PoC+171 d
  4. TodayOct 30, 2026+574 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2025-323755 days apartInsecure Deserialization leads to RCE in BentoML's runner server
    60This week

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python
payload = sock.recv(65536)job = pickle.loads(payload)

Fixed

python
payload = sock.recv(65536)if not hmac.compare_digest(sign(payload), header_sig):    raise PermissionError("invalid signature")job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records