CVE-2021-26529
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS...
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool.
- Record
CVE-2021-26529- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - CVSS 2.0
- 6.4 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:P - Weakness
- CWE-787
- Updated
- 2026-11-02
CVE List No score
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool.
- Record
CVE-2021-26529- Updated
- 2026-11-02
EUVDEUVD-2021-13333 No score
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool.
- Record
EUVD-2021-13333- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-h9wv-3h63-q247 No score
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS...
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool.
- Record
GHSA-h9wv-3h63-q247- Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool.
- Record
CVE-2021-26529- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-26529
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool.
- Record
DEBIAN-CVE-2021-26529- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
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-2021-26529 is a critical vulnerability (CVSS 9.1) in Cesanta Mongoose, published February 8, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.51%, the 74th percentile. Fixed in swupdate 2022.12+dfsg-1.