---
cve: "CVE-2026-59884"
severity: "HIGH"
cvss: 7.5
epss: "35%"
vendor: "pyasn1"
kev: false
exploited: false
published: "2026-07-14 17:17:14"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-02T16:49:10+02:00"
---

# CVE-2026-59884

> 7.5 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- 72e4803405816c371ed3b2cb4be181c47f038406 (Commit)
- 628e36ecbb5277a3f01572ce418ef54271b165a5 (Commit)

## Referenzen

- <https://github.com/pyasn1/pyasn1/security/advisories/GHSA-m4p7-r5rc-7g4j>
- <https://github.com/pyasn1/pyasn1/commit/628e36ecbb5277a3f01572ce418ef54271b165a5>
- <https://github.com/pyasn1/pyasn1/releases/tag/v0.6.4>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-59884) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_