CVE-2021-26505 json
MrSwitch hello.js vulnerable to prototype pollution
published 3y ago modified 4mo ago also GHSA-g3vf-47fv-8f3c , EUVD-2023-2286
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 66%
- public exploits
- 0
- none known
Summary
Prototype pollution vulnerability in MrSwitch hello.js version 1.18.6, allows remote attackers to execute arbitrary code via hello.utils.extend function.
Patch / fix
Is CVE-2021-26505 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- total
- Assessed
- 2y ago
Exploit prediction
1.14% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | hellojs | <1.18.8 |
1.18.8 |
Classification
- Weakness
-
- CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
References
Sources
- CVE List CVE-2021-26505
- GitHub Advisory GHSA-g3vf-47fv-8f3c
- NVD CVE-2021-26505
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