Critical
Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-26530
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 11:41 UTC · Revision 1
Source evidence
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.
osv:CVE-2021-26530
Complete source record
{
"id": "be122f39248332af80fc6b680f8701e3899855c99f4225d8839c84421187ed4d",
"url": "https://osv.dev/vulnerability/CVE-2021-26530",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2021-26530",
"summary": "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.",
"evidence": "osv:CVE-2021-26530",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2021-26530",
"aliases": [
"CVE-2021-26530"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/cesanta/mongoose",
"type": "GIT",
"events": [
{
"introduced": "54250f5fbfa1972b96ef593b457abd6184ea65a0"
},
{
"last_affected": "54250f5fbfa1972b96ef593b457abd6184ea65a0"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:cesanta:mongoose:7.0:*:*:*:*:*:*:*",
"range": [
{
"introduced": "7.0"
},
{
"last_affected": "7.0"
}
],
"source": "CPE_STRING"
}
]
}
}
],
"versions": [
"7.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-26530.json"
}
}
],
"modified": "2026-10-20T10:54:34.240805375Z",
"provider": "osv",
"references": [
"https://github.com/cesanta/mongoose/issues/1204"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2021-26530",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 385610,
"published_at": "2021-02-08T21:15:13.803+00:00"
}