---
title: "CVE-2025-60455: Modular Max Serve has Unsafe Deserialization vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-60455/
description: "CVE-2025-60455 (modular (PyPI)): Unsafe Deserialization vulnerability in Modular Max Serve before 25.6, specifically when the…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-11-18
date_modified: 2025-11-19
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-60455"
kev: false
cvss: 9.3
epss: 0.00333
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-60455: Modular Max Serve has Unsafe Deserialization vulnerability

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.3% , percentile 25: FIRST’s model estimates a 0.3% chance of exploitation activity in the next 30 days, higher than 25% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes modular (PyPI) < 25.6.0, fixed in 25.6.0 . Check your lockfile, including transitive dependencies.

## What it is

Unsafe Deserialization vulnerability in Modular Max Serve before 25.6, specifically when the "--experimental-enable-kvcache-agent" feature is used allowing attackers to execute arbitrary code.

## Affected packages

- PyPI `modular` < 25.6.0 → fixed: 25.6.0

## Affected products (CVE record)

- n/a n/a: see advisory

## Severity

- CISA-ADP CVSS 3.1: 8.4 `CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.33% probability of exploitation activity in the next 30 days; percentile 25.

## Sources

- [GitHub Advisory GHSA-7xcv-9j6c-2fmc](https://github.com/advisories/GHSA-7xcv-9j6c-2fmc)
- [CVE.org record CVE-2025-60455](https://www.cve.org/CVERecord?id=CVE-2025-60455)
- [NVD entry CVE-2025-60455](https://nvd.nist.gov/vuln/detail/CVE-2025-60455)
- [github.com](https://github.com/modular/modular/issues/4795)
- [github.com](https://github.com/modular/modular/blame/main/max/serve/kvcache_agent/kvcache_agent.py#L220)
- [github.com](https://github.com/modular/modular/commit/10620059fb5c47fb0c30e5d21a8ff3b8d622fba4)
- [github.com](https://github.com/modular/modular/commit/ee9c4ab02345dd30bed8b79771b6909ff1b930a1)
- [github.com](https://github.com/modular/modular/commit/b20e749fa892dbe772e890a268002f732164d9f5)
- [oligo.security](https://www.oligo.security/blog/shadowmq-how-code-reuse-spread-critical-vulnerabilities-across-the-ai-ecosystem)

---
Source page: https://erroneo.us/security/cve/CVE-2025-60455/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt