CVE•Published 2026-07-14•Modified 2026-07-21•0 articles on news•4 live references•NVD data

CVE-2026-59885Pyasn1 · Pyasn1

Vulnerability data via NVD (ingested)

CVSS v3.1

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS percentile

Exploit Prediction Scoring System · top 74% of all CVEs

Weaknesses (CWE)

CWE-400Uncontrolled Resource Consumption CWE-407Inefficient Algorithmic Complexity

Description

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER, CER, and DER decoders process OBJECT IDENTIFIER and RELATIVE-OID values in quadratic time relative to the number of arcs, so a small crafted payload containing an OID with many arcs consumes excessive CPU per decode() call and can deny service to applications that decode untrusted ASN.1 data. The corresponding encoders have the same quadratic behavior when an application re-encodes previously decoded attacker-supplied values. This issue is fixed in version 0.6.4.

Timeline

Published 2026-07-14

Modified 2026-07-21

External references

NVD MITRE Exploit-DB VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-59885

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Pyasn1 Pyasn1"

All exposed Pyasn1 Pyasn1 instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Pyasn1"

HTTP body or banner mentions "Pyasn1" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-59885