# jinjava has Sandbox Bypass via JavaType-Based Deserialization

Advisory record · `GHSA-m49c-g9wr-hv6v`

- **Identifiers:** `GHSA-m49c-g9wr-hv6v` · `CVE-2025-59340`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-1336](https://cwe.mitre.org/data/definitions/1336.html)
- **Tags:** [Code injection](https://agentprime.io/advisories/tag/code-injection.md)
- **Published:** 17 Sept 2025
- **Updated:** 31 Jul 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 17 Sept 2025, 19:56 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `com.hubspot.jinjava:jinjava` (Maven): affected `>=2.8.0, <2.8.1 || >=2.7.0, <2.7.5`; fixed in `2.8.1`, `2.7.5`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Jinjava versions 2.8.0 before 2.8.1 and 2.7.0 before 2.7.5 (Maven com.hubspot.jinjava:jinjava) contain a sandbox bypass. An attacker who can supply template content can use JavaType-based deserialization to instantiate arbitrary classes, which can read local files, perform server-side requests, and possibly lead to remote code execution. Upgrade to version 2.8.1 or 2.7.5. The source gives few details on the exact attack conditions.

Written 2 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.022, the 82nd percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:19 UTC: First seen by agentprime
- 31 Oct 2026, 14:19 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-m49c-g9wr-hv6v)

## Sources

- [GitHub Advisory Database: GHSA-m49c-g9wr-hv6v](https://github.com/advisories/GHSA-m49c-g9wr-hv6v)
- [OSV: GHSA-m49c-g9wr-hv6v](https://osv.dev/vulnerability/GHSA-m49c-g9wr-hv6v)
- <https://github.com/HubSpot/jinjava/security/advisories/GHSA-m49c-g9wr-hv6v>
- <https://nvd.nist.gov/vuln/detail/CVE-2025-59340>
- <https://github.com/github/advisory-database/pull/8141>
- <https://github.com/HubSpot/jinjava/commit/66df351e7e8ad71ca04dcacb4b65782af820b8b1>
- <https://github.com/HubSpot/jinjava>
- <https://github.com/HubSpot/jinjava/releases/tag/jinjava-2.7.5>
- <https://github.com/HubSpot/jinjava/releases/tag/jinjava-2.8.1>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-m49c-g9wr-hv6v>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-m49c-g9wr-hv6v/>. Everything for agents: <https://agentprime.io/llms.txt>.