CVE-2021-3645
Prototype Pollution in viking04/merge
merge is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Prototype Pollution in viking04/merge
merge is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
- Record
CVE-2021-3645- CVSS 3.0
- 6.8 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-1321
- Updated
- 2026-11-02
EUVDEUVD-2021-2043
merge is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
- Record
EUVD-2021-2043- CVSS 3.0
- 6.8 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-cqqh-49mx-fq63
merge vulnerable to Prototype Pollution
merge is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
- Record
GHSA-cqqh-49mx-fq63- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-915, CWE-1321
- Updated
- 2026-11-02
NVD
merge is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
- Record
CVE-2021-3645- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 6.8 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-1321
- Updated
- 2026-11-02
OSV
merge is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
- Record
CVE-2021-3645- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-cqqh-49mx-fq63
merge vulnerable to Prototype Pollution
merge is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
- Record
GHSA-cqqh-49mx-fq63- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-1321, CWE-915
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@viking04/mergenpm |
before 1.0.2 | 1.0.2 |
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-2021-3645 is a medium vulnerability (CVSS 6.8) in Merge Project Merge, published September 10, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.43%, the 73rd percentile. Fixed in @viking04/merge 1.0.2.