#VU106918 Incorrect Regular Expression in Enterprise Chat and Email - CVE-2025-20139

Vulnerability identifier: #VU106918

Vulnerability risk: High

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2025-20139

CWE-ID: CWE-185

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Enterprise Chat and Email
Other software / Other software solutions

Vendor: Cisco Systems, Inc

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient input validation when processing regular expressions in chat messaging features. A remote attacker can pass specially crafted data to the application and perform regular expression denial of service (ReDos) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Enterprise Chat and Email: 12.5 - 12.6

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External links
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ece-dos-tC6m9GZ8

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.