CVE-2021-3783
Cross-site Scripting (XSS) - Reflected in yourls/yourls
yourls is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Cross-site Scripting (XSS) - Reflected in yourls/yourls
yourls is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- Record
CVE-2021-3783- CVSS 3.0
- 6.6 Medium
CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-2041
yourls is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- Record
EUVD-2021-2041- CVSS 3.0
- 6.6 Medium
CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-cpq8-x35g-m439
Cross-site Scripting in yourls
yourls is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in arbitrary path handling.
- Record
GHSA-cpq8-x35g-m439- CVSS 3.0
- 6.6 Medium
CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
yourls is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- Record
CVE-2021-3783- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 3.0
- 6.6 Medium
CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
yourls is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- Record
CVE-2021-3783- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-cpq8-x35g-m439
Cross-site Scripting in yourls
yourls is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in arbitrary path handling.
- Record
GHSA-cpq8-x35g-m439- CVSS 3.0
- 6.6 Medium
CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
yourls/yourlsPackagist |
through 1.8.2 | None known |
yourls/yourlsPackagist |
through 1.8.2, plus listed versions 1.7.11.7.21.7.31.7.41.7.5 Show 4 moreShow less1.7.61.7.91.81.8.1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-3783 is a medium vulnerability (CVSS 6.6) in Yourls, published September 15, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.70%, the 53rd percentile. No source names a fixed version.