The resolution SAML SSO apps for Atlassian products allow a remote attacker to login to a user account when only the username is known (i.e…

published 2021-08-02 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-24322

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.5%; EPSS 1.5% chance of exploitation in 30 days, percentile 75%
public exploits: 0; none known

The resolution SAML SSO apps for Atlassian products allow a remote attacker to login to a user account when only the username is known (i.e., no other authentication is provided). The fixed versions are for Jira: 3.6.6.1, 4.0.12, 5.0.5; for Confluence 3.6.6, 4.0.12, 5.0.5; for Bitbucket 2.5.9, 3.6.6, 4.0.12, 5.0.5; for Bamboo 2.5.9, 3.6.6, 4.0.12, 5.0.5; and for Fisheye 2.5.9.

Patch / fix

fixed in 1

atlassian saml_single_sign_on 2.5.9, 3.5.6, 3.6.6, 3.6.6.1, 4.0.12, 5.0.5

Exploit prediction

1.54% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.8	CVSS:3.1/AC:L/AV:N/A:H/C:H/I:H/PR:N/S:U/UI:N
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness

CWE-306 Missing Authentication for Critical Functionality

References

wiki.resolution.de /doc/saml-sso/5.0.x/all/security-advisories/2021-07-29-authentication-bypass-network-attacker-can-login-to-use
third-party-advisory

Sources

CVE List CVE-2021-37843
NVD CVE-2021-37843

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary