Security update for python-cbor2 SUSE Patch security@suse.de SUSE Security Team openSUSE-SU-2025-20133-1 Final 1 1 2025-12-02T13:51:41Z current 2025-12-02T13:51:41Z 2025-12-02T13:51:41Z cve-database/bin/generate-cvrf.pl 2017-02-24T01:00:00Z Security update for python-cbor2 This update for python-cbor2 fixes the following issues: - CVE-2025-64076: Fixed bug in decode_definite_long_string() that causes incorrect chunk length calculation (bsc#1253746). Already fixed in release 5.6.3: - CVE-2024-26134: Fixed potential crash when hashing a CBORTag (bsc#1220096). The CVRF data is provided by SUSE under the Creative Commons License 4.0 with Attribution (CC-BY-4.0). openSUSE-Leap-16.0-91 Copyright SUSE LLC under the Creative Commons License 4.0 with Attribution (CC-BY-4.0) https://www.suse.com/support/security/rating/ SUSE Security Ratings https://bugzilla.suse.com/1220096 SUSE Bug 1220096 https://bugzilla.suse.com/1253746 SUSE Bug 1253746 https://www.suse.com/security/cve/CVE-2024-26134/ SUSE CVE CVE-2024-26134 page https://www.suse.com/security/cve/CVE-2025-64076/ SUSE CVE CVE-2025-64076 page openSUSE Leap 16.0 python313-cbor2-5.6.5-160000.3.1 python313-cbor2-5.6.5-160000.3.1 as a component of openSUSE Leap 16.0 cbor2 provides encoding and decoding for the Concise Binary Object Representation (CBOR) (RFC 8949) serialization format. Starting in version 5.5.1 and prior to version 5.6.2, an attacker can crash a service using cbor2 to parse a CBOR binary by sending a long enough object. Version 5.6.2 contains a patch for this issue. CVE-2024-26134 openSUSE Leap 16.0:python313-cbor2-5.6.5-160000.3.1 important To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch". https://www.suse.com/security/cve/CVE-2024-26134.html CVE-2024-26134 https://bugzilla.suse.com/1220096 SUSE Bug 1220096 Multiple vulnerabilities exist in cbor2 through version 5.7.0 in the decode_definite_long_string() function of the C extension decoder (source/decoder.c): (1) Integer Underflow Leading to Out-of-Bounds Read (CWE-191, CWE-125): An incorrect variable reference and missing state reset in the chunk processing loop causes buffer_length to not be reset to zero after UTF-8 character consumption. This results in subsequent chunk_length calculations producing negative values (e.g., chunk_length = 65536 - buffer_length), which are passed as signed integers to the read() method, potentially triggering unlimited read operations and resource exhaustion. (2) Memory Leak via Missing Reference Count Release (CWE-401): The main processing loop fails to release Python object references (Py_DECREF) for chunk objects allocated in each iteration. For CBOR strings longer than 65536 bytes, this causes cumulative memory leaks proportional to the payload size, enabling memory exhaustion attacks through repeated processing of large CBOR payloads. Both vulnerabilities can be exploited remotely without authentication by sending specially-crafted CBOR data containing definite-length text strings with multi-byte UTF-8 characters positioned at 65536-byte chunk boundaries. Successful exploitation results in denial of service through process crashes (CBORDecodeEOF exceptions) or memory exhaustion. The vulnerabilities affect all applications using cbor2's C extension to process untrusted CBOR data, including web APIs, IoT data collectors, and message queue processors. Fixed in commit 851473490281f82d82560b2368284ef33cf6e8f9 pushed with released version 5.7.1. CVE-2025-64076 openSUSE Leap 16.0:python313-cbor2-5.6.5-160000.3.1 important To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch". https://www.suse.com/security/cve/CVE-2025-64076.html CVE-2025-64076 https://bugzilla.suse.com/1253746 SUSE Bug 1253746