What is CVE-2021-26530?

CVE-2021-26530 is a critical-severity vulnerability in Cesanta Mongoose, classified under Out-of-bounds Write. CVSS score: 9.1/10. Published 2021-02-08.

How severe is CVE-2021-26530?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Is CVE-2021-26530 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Cesanta Mongoose

CVE-2021-26530

The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 (compiled with OpenSSL support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool.

Vulnerability class: Buffer Overflow

EPSS: 0.015 (70.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

Affected products

Cesanta Mongoose — versions 7.0
N/a — versions n/a

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

References

cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2021-26530?: CVE-2021-26530 is a critical-severity vulnerability in Cesanta Mongoose, classified under Out-of-bounds Write. CVSS score: 9.1/10. Published 2021-02-08.
How severe is CVE-2021-26530?: Critical severity. CVSS v3 base score is 9.1 out of 10.
Is CVE-2021-26530 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.