Uncontrolled Recursion in py-asn1 - CVE-2026-30922
Published: April 27, 2026
Vulnerability identifier: #VU128152
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-30922
CWE-ID: CWE-674
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: pyasn1.sourceforge.net
Affected software:
py-asn1
py-asn1
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled recursion in the pyasn1 BER decoder when decoding deeply nested ASN.1 data with indefinite-length constructed types. A remote attacker can supply a specially crafted payload containing nested SEQUENCE or SET tags to cause a denial of service.
Services that parse untrusted ASN.1 data may terminate with a RecursionError or exhaust available memory.
How to mitigate CVE-2026-30922
Install security update from vendor's website.