---
title: "CVE-2026-25526: JinJava Bypass through ForTag leads to Arbitrary Java Execution"
url: https://erroneo.us/security/cve/CVE-2026-25526/
description: "CVE-2026-25526 (com.hubspot.jinjava:jinjava (Maven)): JinJava is a Java-based template engine based on django template syntax, adapted to render jinja…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-02-04
date_modified: 2026-02-05
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-25526"
kev: false
cvss: 9.8
epss: 0.01003
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-25526: JinJava Bypass through ForTag leads to Arbitrary Java Execution

**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 1.0% , percentile 63: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 63% of all scored CVEs (moderate). 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 com.hubspot.jinjava:jinjava (Maven) >= 2.8.0, < 2.8.3, fixed in 2.8.3 ; com.hubspot.jinjava:jinjava (Maven) < 2.7.6, fixed in 2.7.6 . Check your lockfile, including transitive dependencies.

## What it is

JinJava is a Java-based template engine based on django template syntax, adapted to render jinja templates. Prior to versions 2.7.6 and 2.8.3, JinJava is vulnerable to arbitrary Java execution via bypass through ForTag. This allows arbitrary Java class instantiation and file access bypassing built-in sandbox restrictions. This issue has been patched in versions 2.7.6 and 2.8.3.

## Affected packages

- Maven `com.hubspot.jinjava:jinjava` >= 2.8.0, < 2.8.3 → fixed: 2.8.3
- Maven `com.hubspot.jinjava:jinjava` < 2.7.6 → fixed: 2.7.6

## Affected products (CVE record)

- HubSpot jinjava: < 2.7.6, < 2.8.3

## Severity

- GitHub_M CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 1.00% probability of exploitation activity in the next 30 days; percentile 63.

## Sources

- [GitHub Advisory GHSA-gjx9-j8f8-7j74](https://github.com/advisories/GHSA-gjx9-j8f8-7j74)
- [CVE.org record CVE-2026-25526](https://www.cve.org/CVERecord?id=CVE-2026-25526)
- [NVD entry CVE-2026-25526](https://nvd.nist.gov/vuln/detail/CVE-2026-25526)
- [github.com](https://github.com/HubSpot/jinjava/security/advisories/GHSA-gjx9-j8f8-7j74)
- [github.com](https://github.com/HubSpot/jinjava/commit/3d02e504d8bbb13bf3fe019e9ca7b51dfce7a998)
- [github.com](https://github.com/HubSpot/jinjava/commit/c7328dce6030ac718f88974196035edafef24441)
- [github.com](https://github.com/HubSpot/jinjava/releases/tag/jinjava-2.7.6)
- [github.com](https://github.com/HubSpot/jinjava/releases/tag/jinjava-2.8.3)

---
Source page: https://erroneo.us/security/cve/CVE-2026-25526/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt