What is CVE-2021-3961?

CVE-2021-3961 is a medium-severity vulnerability in Snipe Snipe/snipe-It, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-11-19.

How severe is CVE-2021-3961?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Is CVE-2021-3961 known to be exploited?

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

XSS in Snipe Snipe/snipe-It

CVE-2021-3961

snipe-it is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-11-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (53.3th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 53.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.008 · change: +0.000

Affected products

Snipe Snipe/snipe-It — versions unspecified
Snipeitapp Snipe-It

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

References

huntr.dev/bounties/5987aed5-6613-4937-8a3e-d48009b7da10 (Exploit, Patch, Third Party Advisory, Issue Tracking)
github.com/snipe/snipe-it/commit/7ce5993f5ae9d713a0955c2fd8e2dff7a7ce886e (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3961?: CVE-2021-3961 is a medium-severity vulnerability in Snipe Snipe/snipe-It, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-11-19.
How severe is CVE-2021-3961?: Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2021-3961 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.