CVE-2026-55154 espocrm CVE debrief

Who should care

Defenders responsible for EspoCRM instances, especially those with sensitive data, should assess exposure and apply the patch in version 9.3.9. They should also verify exposure in EspoCRM instances and monitor for suspicious activity. Security teams and vulnerability management teams should prioritize verifying exposure and applying the patch.

Why it matters

CVE-2026-55154 is a vulnerability in EspoCRM that allows an authenticated low-privileged user to store a free-text value whose formula trigger is preceded by whitespace or a control character, potentially leading to outbound data disclosure and command execution.

• Potential outbound data disclosure when a privileged user opens the exported file
• Potential command execution on legacy configurations with DDE enabled
• Verification of exposure in EspoCRM instances is required
• Patch application in version 9.3.9 is required

Technical summary

The vulnerability is caused by the sanitizeCellValue() function in EspoCRM only inspecting the first byte of user input. An authenticated low-privileged user can store a free-text value whose formula trigger is preceded by whitespace or a control character, causing CSV or XLSX export to omit the leading single-quote formula-neutralization prefix. This allows outbound data disclosure and, on legacy configurations with DDE enabled, command execution when a privileged user opens the exported file and accepts applicable spreadsheet security prompts.

Defensive priority

Defenders should prioritize verifying exposure in EspoCRM instances, especially those with sensitive data, and apply the patch in version 9.3.9.

Recommended defensive actions

• Verify exposure in EspoCRM instances, especially those with sensitive data
• Apply the patch in version 9.3.9
• Monitor for suspicious activity in EspoCRM instances
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, its impact, and the fixed version. However, there is limited information on exploitation, victims, or business impact. Defenders should verify exposure in EspoCRM instances, especially those with sensitive data, and apply the patch in version 9.3.9. The sanitizer bypass allows an authenticated low-privileged user to store a free-text value whose formula trigger is preceded by whitespace or a control character, causing CSV or XLSX export to omit the leading single' -

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.