9.8

CVE-2026-62644: roundcube webmail Authentication Bypass by Spoofing

CVSS: 9.8v3.1CriticalAnalyzed
AliasesUBUNTU-CVE-2026-62644DEBIAN-CVE-2026-62644
Published 14-07-2026Last modified 14-07-2026
Open JSON

Vulnerability summary

CVE-2026-62644 is a critical (CVSS 9.8) Authentication Bypass by Spoofing vulnerability in roundcube webmail. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 41.8% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
0.50%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 1
MGASA-2026-0332MGASA-2026-0333OPENSUSE-SU-2026:12169-1

Timeline

  1. 14-07-2026
    PublishedVulnerability first disclosed.
  2. 14-07-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.50%

Chance of exploitation in the next 30 days

Percentile

42%

Versus all other CVEs

30-day change

0.00 pp

From 0.50% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.50%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • roundcube< 1.6.5+dfsg-1+deb12u10 | < 1.6.17+dfsg-0+deb13u1 | < 1.6.17+dfsg-1
Roundcube1 product
  • webmail≥ 1.6.0, < 1.6.17 | ≥ 1.7.0, < 1.7.2
Ubuntu1 product
  • roundcubeAll versions (No fix recorded)

3 vendors · 3 products

References

10 links