Vulnerability · Published Aug 17, 2026 · Assigned by VulnCheck
CVE-2026-75106OpnForm Editable Submission Secret Derivation via Empty Hashids Salt
Critical 9.1
In plain English
A critical-severity security flaw in OpnForm from OpnForm. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).
Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.4%top 65.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
OpnForm derives editable-submission secrets from sequential row identifiers using Hashids with an empty default salt, allowing unauthenticated attackers to compute hashes for any submission. Attackers can read other respondents' full submission data through the submission-fetch endpoint or overwrite submissions by supplying predicted hashes to the answer endpoint.
Affected products (as reported)
Weakness: CWE-340 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
References
- GitHub Issue #1259 issue-tracking
- https://github.com/OpnForm/OpnForm product
- Fix editable submission identifiers (#1173) patch
- OpnForm v2.0.2 Release Notes release-notes
- VulnCheck Advisory: OpnForm Editable Submission Secret Derivation via Empty Hashids Salt third-party-advisory