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Fencer Intel
low 3.1

CVE-2026-76078 json

Probo: Broken access control in public e-signature API

published 4mo ago modified 14h ago also GHSA-22xj-f767-ppw6 , EUVD-2026-123667

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository getprobo/probo. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
3.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
—
no EPSS score yet
public exploits
0
none known

Summary

Probo is a self-hostable governance, risk, and compliance (GRC) platform built for engineering and security teams. Prior to version 0.224.0, the public Trust Center GraphQL API exposes acceptElectronicSignature and recordSigningEvent, both gated only by @authentication(required: PRESENT) @sessionOnly — any self-provisioned trust center identity can call them. The underlying esign.Service.AcceptSignature and esign.Service.recordEvent build the tenant scope from the client-supplied signatureId GID (coredata.NewScopeFromObjectID(req.SignatureID)) and load the signature by that GID. At no point do they verify that the signature belongs to the caller or that the caller's email matches the signature's SignerEmail. As a result, any authenticated trust-center visitor who possesses another visitor's signature GID can: (1) complete that visitor's NDA signature — overwriting signer name/IP/UA with attacker data and setting status to Accepted, which triggers the sealing worker to generate a completion certificate; (2) inject arbitrary audit-trail events into any signature's log. Both attacks defeat the non-repudiation and integrity guarantees of the e-signature system. This issue has been patched in version 0.224.0.

Patch / fix

Is CVE-2026-76078 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CVSS scores

assigned by version score vector
CNA 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected products

  • getprobo probo

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key
  • CWE-862 Missing Authorization

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of getprobo/probo published their own advisory on GitHub. Reviewed sources take precedence over it.