CVE-2021-45936 json
wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow in MqttDecode_Disconnect (called from MqttClient_DecodePacket and MqttClient_WaitType…
published 2021-12-31 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-32645
- cvss
- 5.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 60%
- public exploits
- 0
- none known
Summary
wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow in MqttDecode_Disconnect (called from MqttClient_DecodePacket and MqttClient_WaitType).
Patch / fix
Exploit prediction
0.92% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/google/oss-fuzz-vulns/blob/main/vulns/wolfmqtt/OSV-2021-1348.yaml referenced PoC, tagged "exploit" by a source, unverified
- bugs.chromium.org https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=39053 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:N/A:P |
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
-
github.com
/wolfSSL/wolfMQTT/commit/84d4b53122e0fa0280c7872350b89d5777dabbb2
patch, third-party-advisory
-
github.com
/google/oss-fuzz-vulns/blob/main/vulns/wolfmqtt/OSV-2021-1348.yaml
exploit, third-party-advisory
-
bugs.chromium.org
/p/oss-fuzz/issues/detail?id=39053
exploit, issue-tracking, third-party-advisory
Sources
- CVE List CVE-2021-45936
- NVD CVE-2021-45936
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.