CVE-2021-26073 json
Broken Authentication in Atlassian Connect Express
published 2021-04-16 5 y ago modified 2026-06-17 4 mo ago also GHSA-4v96-m8xv-x83v , EUVD-2021-12896
- cvss
- 7.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 61%
- public exploits
- 0
- none known
Summary
Broken Authentication in Atlassian Connect Express (ACE) from version 3.0.2 before version 6.6.0: Atlassian Connect Express is a Node.js package for building Atlassian Connect apps. Authentication between Atlassian products and the Atlassian Connect Express app occurs with a server-to-server JWT or a context JWT. Atlassian Connect Express versions from 3.0.2 before 6.6.0 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.
Patch / fix
- npm atlassian-connect-express 6.6.0
- Atlassian Atlassian Connect Express (ACE) 6.6.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 20 mo ago
Exploit prediction
0.95% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N |
| NVD | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N |
| CNA | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N |
| NVD | 2.0 | 4.0 | AV:N/AC:L/Au:S/C:N/I:P/A:N |
| GitHub | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | atlassian-connect-express | >=3.0.2, <6.6.0 |
6.6.0 |
Affected products
- Atlassian Atlassian Connect Express (ACE)
Classification
References
-
confluence.atlassian.com
/pages/viewpage.action?pageId=1051986099
web, vendor-advisory
-
community.developer.atlassian.com
/t/action-required-atlassian-connect-vulnerability-a%5B%E2%80%A6%5Dypass-of-app-qsh-verification-via-context-j
web
-
security.netapp.com
/advisory/ntap-20210604-0004/
third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-26073
advisory
-
security.netapp.com
/advisory/ntap-20210604-0004
web
-
bitbucket.org
/atlassian/atlassian-connect-express
package
Sources
- CVE List CVE-2021-26073
- GitHub Advisory GHSA-4v96-m8xv-x83v
- NVD CVE-2021-26073
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