CVE-2026-54433: In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, there is Stored Cross-Site Scripting (XSS) via a cr

Routine

HIGH 7.2REMOTEUPGRADE

CVE-2026-54433 is a high-severity flaw (CVSS 7.2) affecting webmail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, there is Stored Cross-Site Scripting (XSS) via a crafted plain-text email message. The attacker-controlled JavaScript executes within the victim's authenticated session simply by opening or previewing the message (zero-click).

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 77%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-07-14
Last modified	2026-10-24

Publisher (CNA): MITRE · Vendor: roundcube

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-14 17:17 UTCPublished CVE record published
2026-10-24 21:10 UTCUpdated Record last modified

roundcube webmail UPGRADE

Affected: < 1.6.17 · >= 1.7.0 and < 1.7.2

Fixed in: 1.6.17, 1.7.2

Safe to downgrade to: a release before 1.7.0

1. Check installed version

apt-cache policy webmail || rpm -q webmail || webmail --version

2. UPGRADE to 1.6.17 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade webmail

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade webmail

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.7.0 (Debian / Ubuntu)

apt-cache madison webmail sudo apt install webmail=<VERSION_BEFORE_1.7.0> sudo apt-mark hold webmail

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list webmail sudo dnf downgrade webmail-<VERSION_BEFORE_1.7.0> sudo dnf versionlock add webmail

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Advisories and coverage

Official advisories

Roundcube News: Roundcube Webmail 1.7.2 2026-07-05
Roundcube News: Roundcube Webmail 1.6.17 2026-07-05

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-54433?

webmail: upgrade to 1.6.17, 1.7.2. Exact commands for each OS are on this page.

Is CVE-2026-54433 being exploited?

CVE-2026-54433 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-54433 affect?

CVE-2026-54433 affects webmail. Severity is high (CVSS 7.2). In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, there is Stored Cross-Site Scripting (XSS) via a crafted plain-text email message. The attacker-controlled JavaScript executes within the victim's authenticated session simply by op

How urgent is CVE-2026-54433?

Priority 36/100. High severity; Remotely exploitable, no login, no user action

Software pages

Roundcube vulnerabilities

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References

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