CVE-2023-29827 — ejs v3

ejs v3.1.9 is vulnerable to server-side template injection. If the ejs file is controllable, template injection can be implemented through the configuration settings of the closeDelimiter parameter. NOTE: this is disputed by the vendor because the render function is not intended

01What is this vulnerability?

ejs v3.1.9 is vulnerable to server-side template injection. If the ejs file is controllable, template injection can be implemented through the configuration settings of the closeDelimiter parameter. NOTE: this is disputed by the vendor because the render function is not intended to be used with untrusted input.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-05-04T00:00:00.000Z
• Last modified: 2025-01-29T20:47:30.293Z

09References

• github.com — https://github.com/mde/ejs/issues/720
• github.com — https://github.com/mde/ejs/blob/main/SECURITY.md#out-of-scope-vulnerabilities