CVE-2026-59994 — EspoCRM: Pre-authentication stored HTML injection in stream notification emails about email received
EspoCRM is an open source customer relationship management application. Prior to 9.3.9, an unauthenticated remote attacker can send an email to a monitored group or IMAP address, including an email-to-Case address, and place arbitrary HTML in its plain-text body. EspoCRM stores that body and renders it without escaping in Email Received stream notification emails sent to users following the related record, allowing HTML injection and, in mail clients that execute it, JavaScript execution. Earlier sanitization for Post and Mention notifications did not cover this notification path. This issue is fixed in version 9.3.9.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Espocrm Espocrm).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (cross-site scripting), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 4.3 | CVSS 3.1 | Medium | 2.8 | 1.4 | security-advisories@github.com via NIST National Vulnerability Database |
| 4.3 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Monitor CSP violation reports and script payloads in reflected parameters.
Timeline
What happened to this CVE, newest first.
- 2026
- Source status changed · Published → Deferred
- Record published
- Affected products added · espocrm/espocrm
- CVSS changed · 4.3
- Source status changed · → Published
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 15, 2026 – Oct 15, 2026
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-75505 EspoCRM: Access control bypass in Mass Update letting regular user with Mass Update permission read any attachment 1h
- Medium CVE-2026-63130 EspoCRM: Admin path traversal in LabelManager (Custom Label saving) allows arbitrary `.json` file read, write and delete 2h
- Medium CVE-2026-77460 EspoCRM: Mass email template renderer leaks restricted record fields 2h
- Medium CVE-2026-55154 EspoCRM: CSV/Formula Injection sanitizer bypass via leading whitespace/control characters in export 2h
- High CVE-2026-53574 EspoCRM: Blind SQL injection via streamAttachments where-clause complex expression 2h
- Low CVE-2026-53575 EspoCRM: Persistent XSS via CSP nonce injection in applicationName setting by admin user 2h
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-59994 is "EspoCRM: Pre-authentication stored HTML injection in stream notification emails about email received", rated Medium. It affects Espocrm (Espocrm); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.3 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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