Is CVE-2026-33753 actively exploited?

No active exploitation of CVE-2026-33753 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-33753 be exploited remotely?

No. CVE-2026-33753 requires local access to exploit.

What is the CVSS score of CVE-2026-33753?

CVE-2026-33753 has a CVSS score of 6.2 (MEDIUM).

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MEDIUM

CVE-2026-33753

CWE-295Published: April 8, 2026· Updated: Apr 8, 2026

6.2

CVSS v3.1

EPSS:0.00%probability of exploitation in 30 daysPercentile:0.1th

Official Description

rfc3161-client is a Python library implementing the Time-Stamp Protocol (TSP) described in RFC 3161. Prior to 1.0.6, an Authorization Bypass vulnerability in rfc3161-client's signature verification allows any attacker to impersonate a trusted TimeStamping Authority (TSA). By exploiting a logic flaw in how the library extracts the leaf certificate from an unordered PKCS#7 bag of certificates, an attacker can append a spoofed certificate matching the target common_name and Extended Key Usage (EKU) requirements. This tricks the library into verifying these authorization rules against the forged certificate while validating the cryptographic signature against an actual trusted TSA (such as FreeTSA), thereby bypassing the intended TSA authorization pinning entirely. This vulnerability is fixed in 1.0.6.

NVD Source

Technical Analysis

CVE-2026-33753 requires local access, meaning attackers must already have a foothold on the target system.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 6.2.