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.
INFO
Published Date :
2026-04-08T14:54:59.704Z
Last Modified :
2026-04-08T16:12:57.796Z
Source :
GitHub_M
AFFECTED PRODUCTS
The following products are affected by CVE-2026-33753 vulnerability.
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REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2026-33753.
