Vulnerability from bitnami_vulndb
Circles' remote-instance signature verification fetches the attacker-supplied keyId URL before trust in the remote instance is established, and explicitly allows local/private addresses for this request, bypassing Nextcloud's core SSRF protections. The public, unauthenticated endpoints POST /apps/circles/event/ and POST /apps/circles/incoming/ reach this code path, allowing any unauthenticated user to force the server to issue a GET request to an internal address.
The response body of the internal request is never returned to the requester, so this is blind SSRF: an attacker can determine whether an internal service is reachable, but cannot read its response contents through this endpoint alone.
{
"affected": [
{
"package": {
"ecosystem": "Bitnami",
"name": "nextcloud",
"purl": "pkg:bitnami/nextcloud"
},
"ranges": [
{
"events": [
{
"introduced": "31.0.0"
},
{
"fixed": "34.0.1"
}
],
"type": "SEMVER"
}
],
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
],
"aliases": [
"CVE-2026-77164"
],
"database_specific": {
"cpes": [
"cpe:2.3:a:nextcloud:nextcloud:*:*:*:*:*:*:*:*"
],
"severity": "Medium"
},
"details": "Circles\u0027 remote-instance signature verification fetches the attacker-supplied keyId URL before trust in the remote instance is established, and explicitly allows local/private addresses for this request, bypassing Nextcloud\u0027s core SSRF protections. The public, unauthenticated endpoints POST /apps/circles/event/ and POST /apps/circles/incoming/ reach this code path, allowing any unauthenticated user to force the server to issue a GET request to an internal address.\n\nThe response body of the internal request is never returned to the requester, so this is blind SSRF: an attacker can determine whether an internal service is reachable, but cannot read its response contents through this endpoint alone.",
"id": "BIT-nextcloud-2026-77164",
"modified": "2026-09-25T12:52:12.177Z",
"published": "2026-09-25T12:27:07.203Z",
"references": [
{
"type": "WEB",
"url": "https://hackerone.com/reports/3303283"
},
{
"type": "WEB",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77164"
}
],
"schema_version": "1.6.2"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.