Postiz is an AI social media scheduling tool. From version 2.16.6 to before version 2.21.7, all SSRF protections added in v2.21.4–v2.21.6 share a fundamental TOCTOU (Time-of-Check-Time-of-Use) vulnerability: isSafePublicHttpsUrl() resolves DNS to validate the target IP, but subsequent fetch() calls resolve DNS independently. An attacker controlling a DNS server can exploit this gap via DNS rebinding to redirect requests to internal network addresses. This issue has been patched in version 2.21.7.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-918"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42346.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "2.16.6"
},
{
"fixed": "2.21.7"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "071143dcb01cdeb9d5d7019892f4c6ff7b19dbeb"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "v2.21.7",
"range": [
{
"fixed": "7236213ea4520bd67b45688c2787d1f4586b3b51"
}
],
"source": "REFERENCES_TAG"
}
]
}