VDB-378373 · CVE-2026-62644 · WID-SEC-2026-2207

Roundcube Webmail up to 1.6.16/1.7.1 Password Plugin Username improper authentication

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.0	$0-$5k	1.33

Summaryinfo

A vulnerability identified as critical has been detected in Roundcube Webmail up to 1.6.16/1.7.1. The affected element is an unknown function of the component Password Plugin. This manipulation of the argument Username causes improper authentication. This vulnerability appears as CVE-2026-62644. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability has been found in Roundcube Webmail up to 1.6.16/1.7.1 and classified as critical. Affected by this vulnerability is some unknown functionality of the component Password Plugin. The manipulation of the argument Username with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, the password plugin of the Roundcube Webmail was subject to username spoofing via session data, which could lead to account takeover.

The advisory is shared at roundcube.net. This vulnerability is known as CVE-2026-62644 since 07/14/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available.

Upgrading to version 1.6.17 or 1.7.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-2207). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

Fedora Linux
Open Source Roundcube

Productinfo

Type

Mail Client Software

Vendor

Roundcube

Name

Webmail

Version

License

free

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: Webmail 1.6.17/1.7.2

Timelineinfo

07/14/2026 Advisory disclosed
07/14/2026 +0 days CVE reserved
07/14/2026 +0 days VulDB entry created
07/15/2026 +1 days VulDB entry last update

Sourcesinfo

Advisory: roundcube.net
Status: Confirmed

CVE: CVE-2026-62644 (🔒)
GCVE (CVE): GCVE-0-2026-62644
GCVE (VulDB): GCVE-100-378373
CERT Bund: WID-SEC-2026-2207 - Roundcube: Mehrere Schwachstellen

Entryinfo

Created: 07/14/2026 18:58
Updated: 07/15/2026 05:11
Changes: 07/14/2026 18:58 (55), 07/15/2026 05:11 (7)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.