CVE-2026-75106

critical

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.

References

https://www.vulncheck.com/advisories/opnform-editable-submission-secret-derivation-via-empty-hashids-salt

https://github.com/OpnForm/OpnForm/releases/tag/v2.0.2

https://github.com/OpnForm/OpnForm/issues/1259

https://github.com/OpnForm/OpnForm/commit/6c67ff0a9bc0ac27ae26b32b8e108a176f8161b1

https://github.com/OpnForm/OpnForm

Details

Source: Mitre, NVD

Published: 2026-08-17

Updated: 2026-08-17

Risk Information

CVSS v2

Base Score: 9.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 9.1

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

Severity: Critical

CVSS v4

Base Score: 9.3

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

Severity: Critical