CVE-2026-80350

high

Assigned by CNA: vulncheck

Published 2026-08-26 · Modified 2026-08-26

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CVSS v3

7.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

CVSS v4 NEW

7.1

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

VIR risk

7.1

Description

OneUptime's webhook target check rejects private and loopback addresses given in IPv4 form and a small set of IPv6 forms, but has no case for the IPv4-mapped IPv6 range. The webhook delivery path calls SSRFProtection.validateWebhookTargetIsSafe, and the host-literal screening inside Common/Server/Utils/SSRFProtection.ts, performed by isBlockedHostnameLiteral, rejects private and loopback IPv4 ranges and tests an IPv6 value against the unspecified address, the loopback, the link-local prefix and the unique-local prefixes. A value such as [::ffff:127.0.0.1] matches none of them. The value is also recognised as an address literal rather than a name, so the path that re-checks addresses obtained from resolution is not taken. The HTTP client treats the mapped form as the embedded IPv4 address and connects to it, so an authenticated project member who can configure a webhook can direct the server at loopback services, private network ranges and link-local metadata endpoints, and the response is recorded where the webhook result can be read. Version 12.0.7 adds handling for the mapped range.

Predictions

Exploit likelihood

80%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

CWEs

CWE-918

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.