HOMEVULNERABILITIESCVE-2021-26074
MEDIUM

CVE-2021-26074

CWE-287Published: April 16, 2021· Updated: Jun 17, 2026

6.5
CVSS v3.1

Official Description

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 from version 1.1.0 before version 2.1.3 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.

NVD Source

Technical Analysis

CVE-2021-26074 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 6.5.

From a weakness classification perspective (CWE-287): Authentication bypass vulnerabilities allow attackers to access protected resources without valid credentials.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Affected Vendors & Products

Atlassian1 product(s)
connect spring boot
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://community.developer.atlassian.com/t/action-required-atlassian-connect-vulnerability-allows-bypass-of-app-qsh-verification-via-context-jwts/47072
ADVISORYhttps://confluence.atlassian.com/pages/viewpage.action?pageId=1051986106
ADVISORYhttps://community.developer.atlassian.com/t/action-required-atlassian-connect-vulnerability-allows-bypass-of-app-qsh-verification-via-context-jwts/47072
ADVISORYhttps://confluence.atlassian.com/pages/viewpage.action?pageId=1051986106

All References (4)

→
https://community.developer.atlassian.com/t/action-required-atlassian-connect-vulnerability-allows-bypass-of-app-qsh-verification-via-context-jwts/47072Vendor Advisory
→
https://confluence.atlassian.com/pages/viewpage.action?pageId=1051986106Vendor Advisory
→
https://community.developer.atlassian.com/t/action-required-atlassian-connect-vulnerability-allows-bypass-of-app-qsh-verification-via-context-jwts/47072Vendor Advisory
→
https://confluence.atlassian.com/pages/viewpage.action?pageId=1051986106Vendor Advisory

Quick Facts

CVE IDCVE-2021-26074
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-287
CISA KEVNo
Affected1 vendor(s)
PublishedApr 16, 2021

Related CVEs (CWE-287)

CVE-2011-2963
10.0
CVE-2002-2417
10.0
CVE-2008-0960
10.0
CVE-2008-2833
10.0
CVE-2010-4279
10.0
CVE-2026-30836
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-26074 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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