Is CVE-2026-69249 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-69249 being exploited in the wild.

How severe is CVE-2026-69249?

High severity, with a CVSS score of 4, published 3 August 2026.

Which products and versions are affected?

cryptography (PyPI) <= 48.0.0, ECOSYSTEM:introduced=0,fixed=49.0.0, ECOSYSTEM:introduced=42.0.0,fixed=49.0.0.

Is there a fix for CVE-2026-69249?

Yes. cryptography (PyPI): upgrade to 49.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-69249 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-69249?

Check whether you run cryptography (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-69249: Pyca Cryptography exponential path-building in X.509 verification

Q: Which products and versions are affected?

cryptography (PyPI) <= 48.0.0, ECOSYSTEM:introduced=0,fixed=49.0.0, ECOSYSTEM:introduced=42.0.0,fixed=49.0.0.

Q: Is there a fix for CVE-2026-69249?

Yes. cryptography (PyPI): upgrade to 49.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-69249 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-69249?

Check whether you run cryptography (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-69249 · Severity: high · CVSS 4 · Published 2026-08-03

A vulnerability in the popular Python 'cryptography' library can allow an attacker to crash or slow down a service by providing a specially crafted security certificate. The library fails to efficiently process certain types of invalid certificate chains, leading to excessive CPU usage. This can result in a denial-of-service (DoS) where the application becomes unresponsive to legitimate users.

Technologies: cryptography (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2026-69249 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-69249 being exploited in the wild.
How severe is CVE-2026-69249?: High severity, with a CVSS score of 4, published 3 August 2026.
Which products and versions are affected?: cryptography (PyPI) <= 48.0.0, ECOSYSTEM:introduced=0,fixed=49.0.0, ECOSYSTEM:introduced=42.0.0,fixed=49.0.0.
Is there a fix for CVE-2026-69249?: Yes. cryptography (PyPI): upgrade to 49.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-69249 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-69249?: Check whether you run cryptography (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

cryptography (PyPI): upgrade to 49.0.0 or later
```
pip install "cryptography>=49.0.0"
```

Technical details

A resource exhaustion vulnerability exists in the X.509 path-building logic of the cryptography library. The `build_chain_inner` function, which is part of the certificate verification process, recursively invokes itself without de-duplicating previously analyzed candidates when resolving invalid chains with duplicate self-signed certificates. While a maximum chain depth exists to prevent infinite recursion, the exponential growth in path-building attempts allows an attacker to trigger significant processing delays (e.g., >5 seconds for a small chain). This can be exploited remotely by providing a crafted certificate chain to any service performing X.509 validation using the affected library. The issue is fixed in version 49.0.0 by tracking and skipping already-seen valid issuers during recursion.

Affected products

pyca cryptography <= 48.0.0

Identifiers

CVE-2026-69249
GHSA-jwv3-5hgf-82ww
PYSEC-2026-3553

Timeline

2026-07-31: advisory: GitHub Advisory published
2026-08-03: disclosed: CVE-2026-69249 disclosed
2026-08-03: patched: Fixed in version 49.0.0

References

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