What is CVE-2021-3863?

CVE-2021-3863 is a medium-severity vulnerability in Snipe Snipe/snipe-It, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-10-19.

How severe is CVE-2021-3863?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2021-3863 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-2021-3863

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

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-10-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (54.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · 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/1dbc8d79-1b53-44a3-a576-faec78f29ba0 (Exploit, Patch, Third Party Advisory)
github.com/snipe/snipe-it/commit/fc5efd857f61f7e45c61db567bb66612bcb53128 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3863?: CVE-2021-3863 is a medium-severity vulnerability in Snipe Snipe/snipe-It, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-10-19.
How severe is CVE-2021-3863?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2021-3863 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.