CVE-2026-33657: EspoCRM is an open source customer relationship management application

Q: How do I fix CVE-2026-33657?

espocrm: upgrade to 9.3.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-33657 being exploited?

CVE-2026-33657 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-33657 affect?

CVE-2026-33657 affects espocrm. Severity is medium (CVSS 4.6). EspoCRM is an open source customer relationship management application. Versions 9.3.3 and below have a stored HTML injection vulnerability that allows any authenticated user with standard (non-administrative) privileges to inject arbitrary

Q: How urgent is CVE-2026-33657?

Priority 23/100. Public exploit reference

Routine

MEDIUM 4.6UPGRADE

CVE-2026-33657 is a medium-severity flaw (CVSS 4.6) affecting espocrm. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

EspoCRM is an open source customer relationship management application. Versions 9.3.3 and below have a stored HTML injection vulnerability that allows any authenticated user with standard (non-administrative) privileges to inject arbitrary HTML into system-generated email notifications by crafting malicious content in the post field of stream activity notes. The vulnerability exists because server-side Handlebars templates render the post field

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.6 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.2% (top 93%)
CISA exploited list	No
Weakness	CWE-80, CWE-116
Published	2026-04-13
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: espocrm

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-13 20:16 UTCPublished CVE record published
2026-06-17 10:37 UTCUpdated Record last modified

espocrm espocrm UPGRADE

Affected: < 9.3.4

Fixed in: 9.3.4

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 9.3.4 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade espocrm

Note

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

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-2026-33657?

espocrm: upgrade to 9.3.4. Exact commands for each OS are on this page.

Is CVE-2026-33657 being exploited?

CVE-2026-33657 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-2026-33657 affect?

CVE-2026-33657 affects espocrm. Severity is medium (CVSS 4.6). EspoCRM is an open source customer relationship management application. Versions 9.3.3 and below have a stored HTML injection vulnerability that allows any authenticated user with standard (non-administrative) privileges to inject arbitrary

How urgent is CVE-2026-33657?

Priority 23/100. Public exploit reference

Related CVEs

CVE-2026-33740 MEDIUM 5.4 UPGRADE EspoCRM is an open source customer relationship management application
CVE-2026-33733 HIGH 7.2 UPGRADE EspoCRM is an open source customer relationship management application
CVE-2026-33659 LOW 3.5 UPGRADE EspoCRM is an open source customer relationship management application
CVE-2026-33656 CRITICAL 9.1 UPGRADE EspoCRM is an open source customer relationship management application
CVE-2026-33534 MEDIUM 4.3 UPGRADE EspoCRM is an open source customer relationship management application

References

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