OpenSignLabs opensignserver - Missing Authentication for Critical Function
Priority MEDIUM 40CWE-306Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-306.
Summary
A missing authentication vulnerability in OpenSignLabs opensignserver through 2.37.0 allows an unauthenticated remote attacker to read arbitrary stored documents via the fileupload Parse cloud function. The function mints MASTER_KEY-signed file access tokens for any caller-supplied URL without performing any session check, defeating the only access control protecting stored contract files.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0061 49th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| OpenSignLabs | opensignserver | up to 2.37.0 | — | No fix listed | CNA |
- opensignserver VendorOpenSignLabs Affected up to 2.37.0 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-72688
- 2026-10-03 Alias added: GHSA-jppp-j33j-6m5q
References
Advisory 1
More OpenSignLabs vulnerabilities
- TI-2026-62535 OpenSign through 2.41.3 Information Disclosure via getDocument CVSS 4.0HIGH 8.7
- TI-2026-50929 OpenSignLabs opensignserver - Authentication Bypass CVSS 3.1HIGH 7.5
- TI-2026-50807 OpenSignLabs OpenSign - Information Disclosure CVSS 3.1HIGH 7.5
- TI-2026-50804 OpenSignLabs OpenSign - Insecure Direct Object Reference CVSS 3.1HIGH 7.5
- TI-2026-50802 OpenSignLabs OpenSign - Insecure Direct Object Reference CVSS 3.1HIGH 7.5
- TI-2026-50930 OpenSignLabs opensignserver - Missing Authorization CVSS 3.1HIGH 7.5
Sources
- CVE-2026-72688 · CVE Program
- CVE-2026-72688 · NVD
- FIRST EPSS
- GHSA-jppp-j33j-6m5q · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences