CVE-2021-46520 json
Cesanta MJS v2.20.0 was discovered to contain a heap buffer overflow via mjs_jprintf at src/mjs_util.c.
published 2022-01-27 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-33196
- cvss
- 7.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 54%
- public exploits
- 0
- none known
Summary
Cesanta MJS v2.20.0 was discovered to contain a heap buffer overflow via mjs_jprintf at src/mjs_util.c.
Exploit prediction
0.73% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/cesanta/mjs/issues/193 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.8 | AV:N/AC:M/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
-
github.com
/cesanta/mjs/issues/193
exploit, issue-tracking, third-party-advisory
Sources
- CVE List CVE-2021-46520
- NVD CVE-2021-46520
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