Description
The checkPassword function in python-kerberos does not authenticate the KDC it attempts to communicate with, which allows remote attackers to cause a denial of service (bad response), or have other unspecified impact by performing a man-in-the-middle attack.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | kerberos | <= 1.2.5 | — | GHSA-mffc-9gx5-99g3 |
| PyPI | kerberos | >= 0.0 | — | PYSEC-2017-49 |
| PyPI | pykerberos | < 1.1.6 | 1.1.6 | GHSA-mffc-9gx5-99g3 |
Advisories 2
- DLA-265-1 pykerberos - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-265-2 pykerberos - regression update Debian Security (DSA / DLA) · Mar 9, 2026