GHSA-qfr5-wjpw-q4c4 — python-ldap
MEDIUMGHSA-qfr5-wjpw-q4c4 is a medium-severity (CVSS 6.5) CWE-1333 vulnerability in python-ldap. A fix is available for python-ldap — see the affected versions and patch details below.
Denial of Service in python-ldap
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.
How urgent is this, really
GHSA-qfr5-wjpw-q4c4 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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 before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions, because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input, a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | python-ldap | all versions | 3.4.0pip install --upgrade 'python-ldap==3.4.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for python-ldap, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update python-ldap to 3.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qfr5-wjpw-q4c4 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-qfr5-wjpw-q4c4 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-qfr5-wjpw-q4c4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat Enterprise Linux 9.0.z is affected by this vulnerability as it includes the vulnerable version of python-ldap (3.3.1). However, the issue was resolved in Red Hat Enterprise Linux 9.2 and later via RHEA-2023:2359, which rebased python-ldap to version 3.4.3 containing the upstream fix. Red Hat Enterprise Linux…
Check input for an excessive amount of backslashes in schemas. More than a dozen backslashes per line are atypical.Source: Red Hat security advisory for GHSA-qfr5-wjpw-q4c4 (CC BY 4.0)
Frequently Asked Questions
Is GHSA-qfr5-wjpw-q4c4 in your dependencies?
O3 Security finds GHSA-qfr5-wjpw-q4c4 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.