CVE-2026-48021: Cert Validation Flaw (CVSS 9.1)

Description

In epa4all, prior to version 2026-05-20, an attacker who can intercept the TLS connection between epa4all and the ePA backend can complete the VAU handshake with attacker-controlled keys and obtain the session encryption keys. All inner HTTP traffic (patient consent decisions, medication data, document operations, authorization tokens, and entitlement queries) becomes readable and modifiable. The attacker can also inject arbitrary requests through the hijacked channel. This issue has been patched in version 2026-05-20.

Is your site exposed to CVE-2026-48021?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0012

Probability of exploitation

0.03%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-295 CWE-295

CWE-347 CWE-347

References

Other References

https://github.com/med-united/epa4all/releases/tag/2026-05-20 https://github.com/med-united/epa4all/security/advisories/GHSA-vvh7-x6c7-46gh https://www.machinespirits.com/advisory/aa49f0

Frequently Asked Questions

What is CVE-2026-48021? +

In epa4all, prior to version 2026-05-20, an attacker who can intercept the TLS connection between epa4all and the ePA backend can complete the VAU handshake with attacker-controlled keys and obtain the session encryption keys. All inner HTTP traffic (patient consent decisions, medication data, document operations, authorization tokens, and entitlement queries) becomes readable and modifiable. The attacker can also inject arbitrary requests through the hijacked channel. This issue has been patched in version 2026-05-20. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-48021? +

CVE-2026-48021 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0012, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-48021? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-44700

Elixir WebRTC is an Elixir implementation of the W3C WebRTC API. Prior to 0.15.1 and 0.16.1, missing DTLS peer certificate …

CVE-2025-9291

A certification validation weakness exists in communication between affected Omada devices and cloud controllers. Certificate identity verification does not adequately …

CVE-2026-0277

An improper certificate validation vulnerability in the Prisma® Access Agent for iOS enables an attacker to perform a man-in-the-middle (MitM) …

CVE-2025-3463

"This issue is limited to motherboards and does not affect laptops, desktop computers, or other endpoints." An insufficient validation vulnerability …

CVE-2025-5279

When the Amazon Redshift Python Connector is configured with the BrowserAzureOAuth2CredentialsProvider plugin, the driver skips the SSL certificate validation step …

CVE-2025-34066

An improper certificate validation vulnerability exists in AVTECH IP cameras, DVRs, and NVRs due to the use of wget with …

CVE-2026-48021