CVE-2026-59884

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Source
https://cve.org/CVERecord?id=CVE-2026-59884
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59884.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-59884
Aliases
  • GHSA-m4p7-r5rc-7g4j
Downstream
Published
2026-07-14T16:41:10.277Z
Modified
2026-07-16T03:48:44.792999086Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
pyasn1 BER/CER/DER decoder denial of service via unbounded long-form tag IDs
Details

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.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59884.json",
    "cwe_ids": [
        "CWE-400"
    ],
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/pyasn1/pyasn1

Affected ranges

Type
GIT
Repo
https://github.com/pyasn1/pyasn1
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
628e36ecbb5277a3f01572ce418ef54271b165a5
Fixed
72e4803405816c371ed3b2cb4be181c47f038406
Database specific 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.6.4"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

0.*
0.2.3
v0.*
v0.2.1
v0.2.2
v0.3.1
v0.3.2
v0.3.3
v0.3.4
v0.3.5
v0.3.6
v0.3.7
v0.4.1
v0.4.2
v0.4.3
v0.4.4
v0.4.5
v0.4.6
v0.4.7
v0.4.8
v0.5.0
v0.5.1
v0.6.0
v0.6.1
v0.6.2
v0.6.3

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59884.json"