What is CVE-2023-45303?

CVE-2023-45303 is a high-severity vulnerability in Thingsboard, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 8.4/10. Published 2023-10-06.

How severe is CVE-2023-45303?

High severity. CVSS v3 base score is 8.4 out of 10.

Is CVE-2023-45303 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Thingsboard

CVE-2023-45303

ThingsBoard before 3.5 allows Server-Side Template Injection if users are allowed to modify an email template, because Apache FreeMarker supports freemarker.template.utility.Execute (for content sent to the /api/admin/settings endpoint).

Published 2023-10-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.4 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.009 (56.8th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Thingsboard

Weakness classification (CWE)

CWE-74 — Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-45303?: CVE-2023-45303 is a high-severity vulnerability in Thingsboard, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 8.4/10. Published 2023-10-06.
How severe is CVE-2023-45303?: High severity. CVSS v3 base score is 8.4 out of 10.
Is CVE-2023-45303 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.