Quick answers
- Is CVE-2026-19553 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-19553 being exploited in the wild.
- How severe is CVE-2026-19553?
- Informational severity, published 30 September 2026.
- Which products and versions are affected?
- Python 3.10 through 3.15.
- Is there a fix for CVE-2026-19553?
- A patch was published on 2026-09-30. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-19553 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-19553?
- Check whether you run Python 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.
Technical details
The ssl.SSLContext.wrap_bio() method failed to enforce that server_hostname must be a non-None, non-empty value when check_hostname is True, unlike the similar wrap_socket() method. An attacker could exploit misconfigured applications by omitting the server_hostname parameter, causing hostname verification to silently fail and accept any certificate. The fix adds parameter validation to raise ValueError when server_hostname is missing or empty under these conditions.
Affected products
- Python Python 3.10 through 3.15
Timeline
- 2026-09-30: disclosed
- 2026-09-30: patched