Broken Authentication in Atlassian Connect Spring Boot

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2021-26074: 0.65% estimated exploitation activity in the next 30 days; percentile 51.25 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Broken Authentication in Atlassian Connect Spring Boot (ACSB) from version 1.1.0 before version 2.1.3. Atlassian Connect Spring Boot is a Java Spring Boot package for building Atlassian Connect apps. Authentication between Atlassian products and the Atlassian Connect Spring Boot app occurs with a server-to-server JWT or a context JWT. Atlassian Connect Spring Boot versions between 1.1.0 - 2.1.2 erroneously accept context JWTs in lifecycle endpoints (such as installation) where only server-to-server JWTs should be accepted, permitting an attacker to send authenticated re-installation events to an app.

Published by the source

10 May 2021, 15:19 UTC

Last modified by the source

1 Feb 2023, 05:05 UTC

Source last checked

26 Oct 2026, 16:06 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-cpcr-74q9-74gp

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# Patch Next advisory brief: CVE-2021-26074

Advisory: Broken Authentication in Atlassian Connect Spring Boot
IDs: CVE-2021-26074, GHSA-cpcr-74q9-74gp
Record: https://patchnext.com/advisories/cve-2021-26074 (revision 1, source checked 26 Oct 2026, 16:06 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: com.atlassian.connect:atlassian-connect-spring-boot-starter 2.1.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven com.atlassian.connect:atlassian-connect-spring-boot-starter: affected >= 1.1.0, < 2.1.3; fixed in 2.1.3

## Suggested inspection (read-only)
- Maven com.atlassian.connect:atlassian-connect-spring-boot-starter: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on com.atlassian.connect:atlassian-connect-spring-boot-starter.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-cpcr-74q9-74gp (GitHub-reviewed advisory GHSA-cpcr-74q9-74gp lists affected ranges: Maven com.atlassian.connect:atlassian-connect-spring-boot-starter >=1.1.0 <2.1.3)

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