# CVE-2026-72544: OpenSignLabs OpenSign audit trail forgery via unauthenticated cloud function

Source: https://junglewise.ai/threats/cve-2026-72544-opensignlabs-opensign-audit-trail-forgery-via-unauthenticated  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-11. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-72544 · Severity: high · CVSS 7.5 · Published 2026-08-11

OpenSign is a free, open-source alternative to DocuSign used for digital document signing and verification. A vulnerability in its Parse cloud function allows attackers to forge audit trail entries—the record of who signed a document and when—without authentication. This undermines the legal validity of signed documents by allowing attackers to fabricate false evidence of document authenticity and non-repudiation.

Technologies: [OpenSignLabs OpenSign](https://junglewise.ai/threats/technologies/opensign). Vendors: [OpenSignLabs](https://junglewise.ai/threats/vendors/opensignlabs).

## Quick answers

**Is CVE-2026-72544 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-72544 being exploited in the wild.

**How severe is CVE-2026-72544?** High severity, with a CVSS score of 7.5, published 11 August 2026.

**Which products and versions are affected?** OpenSignLabs OpenSign through 2.37.0.

**Is there a fix for CVE-2026-72544?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-72544 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-72544?** Check whether you run OpenSignLabs OpenSign at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an authentication bypass and integrity verification flaw in the OpenSign triggerevenet Parse cloud function. The function accepts viewer identity and IP address as unauthenticated, caller-supplied parameters, failing to validate the origin or legitimacy of these inputs. An attacker can craft requests to inject arbitrary audit log entries into any signed document's trail, bypassing non-repudiation protections. The vulnerability affects OpenSign through version 2.37.0 and requires only network reachability to the Parse cloud function endpoint; no prior authentication is necessary. Remediation involves implementing proper authentication checks and validating audit trail inputs server-side before recording them.

## Affected products

- OpenSignLabs OpenSign through 2.37.0

## Timeline

- 2026-08-11: disclosed

## References

- [https://github.com/OpenSignLabs/OpenSign](https://github.com/OpenSignLabs/OpenSign)

## Related threats

- [OpenSignLabs OpenSign information disclosure via user ID enumeration](https://junglewise.ai/threats/cve-2026-72549-opensignlabs-opensign-information-disclosure-via-user-id)
- [OpenSignLabs OpenSign information disclosure in gettenant function](https://junglewise.ai/threats/cve-2026-72548-opensignlabs-opensign-information-disclosure-in-gettenant)
- [OpenSignLabs OpenSign insecure direct object reference in contact update](https://junglewise.ai/threats/cve-2026-72545-opensignlabs-opensign-insecure-direct-object-reference-in-contact)
- [OpenSignLabs OpenSign insecure direct object reference in contact retrieval](https://junglewise.ai/threats/cve-2026-72543-opensignlabs-opensign-insecure-direct-object-reference-in-contact)