Is CVE-2021-26073 in the CISA KEV catalog?

No. CVE-2021-26073 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-26073?

CVE-2021-26073 has a CVSS v3 base score of 7.7 (HIGH).

What is the EPSS score for CVE-2021-26073?

CVE-2021-26073 has an EPSS score of 0.90% (55th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-26073?

Upgrade connect express to 6.6.0 or later.

CVE & CISA-KEV Catalog

CVE-2021-26073

HIGH

7.7

CVSS v3

NVD

Description

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.

CWE-287Improper Authentication

How to fix

Remediation Available

connect expressNVD

Affected:>= 3.0.2, < 6.6.0Fixed in:6.6.0CVE-2021-26073derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeChanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

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

Exploit Intelligence

0.90%probability of exploitation in 30 days

55thpercentile

Moderate risk: more likely to be exploited than 55% of all known CVEs.

References

Vendor Advisory1

confluence.atlassian.com

Third-Party Advisory1

security.netapp.com

Other references1

community.developer.atlassian.com

Related Vulnerabilities

Other CWE-287 (Improper Authentication) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-35082	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2023-35078	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2017-7921	Critical	9.8	100%	KEV	-
CVE-2024-7593	Critical	9.8	100%	KEV	-
CVE-2023-46805	High	8.2	100%	KEV + Ransom	-
CVE-2022-40684	Critical	9.8	100%	KEV + Ransom	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-02-12.