CVE-2026-103902 DigiDoc CVE debrief

Who should care

Defenders and administrators of DigiDoc products should assess exposure and verify versions to ensure the vulnerability is not exploited. This includes reviewing current deployments, checking version numbers against known vulnerable ranges, and applying patches or updates as necessary. Security teams and vulnerability management teams should prioritize this issue due to its high CVSS score and potential operational impacts.

Why it matters

The DigiDoc improper signature verification vulnerability has a high CVSS score of 7.5 and could allow attackers to create forged digital signatures. Defenders should assess exposure, verify versions, and apply patches or updates if available.

• Potential for forged digital signatures to be accepted as valid
• Need for version verification and patching of affected products

Technical summary

The DigiDoc improper signature verification vulnerability allows an attacker to create forged digital signatures that are displayed as valid by affected DigiDoc software. This issue affects libdigidocpp from 4.0.0 before 4.5.0; DigiDoc4 from 4.6.0 before 4.11.0; DigiDoc Android from 2.7.0 before 3.1.0; and DigiDoc iOS from 2.7.0 before 3.1.0. The vulnerability has a high CVSS score of 7.5, indicating a significant risk to affected systems. Defenders should assess exposure, verify versions, and apply patches or updates if available.

Defensive priority

High

Recommended defensive actions

• Assess exposure of DigiDoc products in your environment
• Verify versions of libdigidocpp, DigiDoc4, DigiDoc Android, and DigiDoc iOS
• Apply patches or updates if available
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability and affected products. However, limited information is available on exploitation or victim impact. Defenders should verify the vulnerability details with official sources and assess exposure based on known affected versions. The DigiDoc software is used for digital signatures, and improper verification could lead to security risks if not addressed.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.