6.5

CVE-2021-26074: atlassian atlassian connect spring boot (acsb) Improper Authentication

Modified
AliasesGHSA-cpcr-74q9-74gp
Published 16-04-2021Last modified 12-02-2025

Vulnerability summary

CVE-2021-26074 is a medium (CVSS 6.5) Improper Authentication vulnerability in atlassian atlassian connect spring boot (acsb). EPSS estimates a 0.65% chance of exploitation in the next 30 days, higher than 51.2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.5, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.65%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 16-04-2021
    PublishedVulnerability first disclosed.
  2. 12-02-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.65%

Chance of exploitation in the next 30 days

Percentile

51%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.65% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Atlassian2 products
Com.atlassian.connect1 product
  • atlassian-connect-spring-boot-starter≥ 1.1.0, < 2.1.3

2 vendors · 3 products

References

3 links