CVE-2025-61911
python-ldap has sanitization bypass in ldap.filter.escape_filter_chars
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
python-ldapReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
python-ldap is a lightweight directory access protocol (LDAP) client API for Python. In versions prior to 3.4.5, the sanitization method ldap.filter.escape_filter_chars can be tricked to skip escaping of special characters when a crafted list or dict is supplied as the assertion_value parameter, and the non-default escape_mode=1 is configured. The method ldap.filter.escape_filter_chars supports 3 different escaping modes. escape_mode=0 (default) and escape_mode=2 happen to raise exceptions when a list or dict object is supplied as the assertion_value parameter. However, escape_mode=1 computes without performing adequate logic to ensure a fully escaped return value. If an application relies on the vulnerable method in the python-ldap library to escape untrusted user input, an attacker might be able to abuse the vulnerability to launch ldap injection attacks which could potentially disclose or manipulate ldap data meant to be inaccessible to them. Version 3.4.5 fixes the issue by adding a type check at the start of the ldap.filter.escape_filter_chars method to raise an exception when the supplied assertion_value parameter is not of type str.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | python-ldap | all versions | 3.4.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for python-ldap. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update python-ldap to 3.4.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-61911 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-61911 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-61911. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-61911 in your dependencies?
O3 detects CVE-2025-61911 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.