---
cve: "CVE-2026-69249"
severity: "HIGH"
cvss: 8.7
epss: "0.3%"
vendor: "pyca"
kev: false
exploited: false
published: "2026-08-03 22:16:52"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-23T06:20:48+02:00"
---

# CVE-2026-69249

> 8.7 HIGH · 🧪 PoC

## Beschreibung

python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 42.0.0 through 48.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- e300bbe2f1bec75e5ee7e0ab7b196958831b3db6 (Commit)

## Referenzen

- <https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww>
- <https://github.com/pyca/cryptography/pull/14960>
- <https://github.com/pyca/cryptography/commit/3763aa79b>
- <https://github.com/pyca/cryptography/commit/4a12cf49675a184e47f912b00b04f3a629283582>
- <https://github.com/pypa/advisory-database/tree/main/vulns/cryptography/PYSEC-2026-3553.yaml>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-69249) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_