CVE-2025-59154

CVE-2025-59154 is a medium-severity vulnerability with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-290.

Key facts

Description

Openfire is an XMPP server licensed under the Open Source Apache License. Openfire’s SASL EXTERNAL mechanism for client TLS authentication contains a vulnerability in how it extracts user identities from X.509 certificates. Instead of parsing the structured ASN.1 data, the code calls X509Certificate.getSubjectDN().getName() and applies a regex to look for CN=. This method produces a provider-dependent string that does not escape special characters. In SunJSSE (sun.security.x509.X500Name), for example, commas and equals signs inside attribute values are not escaped. As a result, a malicious certificate can embed CN= inside another attribute value (e.g. OU="CN=admin,"). The regex will incorrectly interpret this as a legitimate Common Name and extract admin. If SASL EXTERNAL is enabled and configured to map CNs to user accounts, this allows the attacker to impersonate another user. The fix is included in Openfire 5.0.2 and 5.1.0.

Frequently asked questions

What is CVE-2025-59154?
Openfire is an XMPP server licensed under the Open Source Apache License. Openfire’s SASL EXTERNAL mechanism for client TLS authentication contains a vulnerability in how it extracts user identities from X.509 certificates. Instead of parsing the structured ASN.1 data, the code calls X509Certificate.getSubjectDN().getName() and applies a regex to look for CN=. This method produces a provider-dependent string that does not escape special characters. In SunJSSE (sun.security.x509.X500Name), for example, commas and equals signs inside attribute values are not escaped. As a result, a malicious certificate can embed CN= inside another attribute value (e.g. OU="CN=admin,"). The regex will incorrectly interpret this as a legitimate Common Name and extract admin. If SASL EXTERNAL is enabled and configured to map CNs to user accounts, this allows the attacker to impersonate another user. The fix is included in Openfire 5.0.2 and 5.1.0.
How severe is CVE-2025-59154?
CVE-2025-59154 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2025-59154 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-59154?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-59154 have an EU (EUVD) identifier?
Yes. CVE-2025-59154 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-29235.
When was CVE-2025-59154 published?
CVE-2025-59154 was published on 2025-09-15 and last updated on 2026-06-17.

References

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