This page tracks the Ubuntu fix status. The vulnerability itself is described on the main CVE page.
View CVE-2026-59884 →
UBUNTU-CVE-2026-59884
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating c...
Original description
The description as published by the source.
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily large integer with CPU cost growing quadratically and to trigger unhandled ValueError exceptions in Python 3.11+ error formatting paths. Any application decoding untrusted BER, CER, or DER input is affected. This issue is fixed in version 0.6.4.
Source: OSV.dev (Open Source Vulnerabilities) OSV
Affected packages
Ubuntu:Pro:14.04:LTS
pyasn1
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:16.04:LTS
pyasn1
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:18.04:LTS
pyasn1
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:20.04:LTS
pyasn1
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
pyasn1
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.4.8-1ubuntu0.3"}]}]
Ubuntu:24.04:LTS
pyasn1
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.4.8-4ubuntu0.3"}]}]
Ubuntu:26.04:LTS
pyasn1
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.6.3-1ubuntu0.1"}]}]
References
- advisory ubuntu.com
- report ubuntu.com
- report cve.org
- report github.com
- report github.com