ReDoS in LDAP schema parser
Key facts
- Attack vector
- —
- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
- Denial of service
- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from GitHub. Impact type from CWE-1333.
Summary
https://github.com/python-ldap/python-ldap/issues/424 ### Impact The LDAP schema parser of python-ldap 3.3.1 and earlier are vulnerable to a regular expression denial-of-service attack. The issue affects clients that use ``ldap.schema`` package to parse LDAP schema definitions from an untrusted source. ### Patches The upcoming release of python-ldap 3.4.0 will contain a workaround to prevent ReDoS attacks. The schema parser refuses schema definitions with an excessive amount of backslashes. ### Workarounds As a workaround, users can check input for excessive amount of backslashes in schemas. More than a dozen backslashes per line are atypical. ### References [CWE-1333](https://cwe.mitre.org/data/definitions/1333.html) ### For more information If you have any questions or comments about this advisory: * Open an issue in [python-ldap](https://github.com/python-ldap/python-ldap) tracker
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | python-ldap (PyPI) | before 3.4.0 | 3.4.0 | Patch available | GHSA-r8wq-qrxc-hmcm |
- python-ldap (PyPI) Vendor— Affected before 3.4.0 Fixed in 3.4.0 Patch available GHSA-r8wq-qrxc-hmcm
Remediation
- Fix · GHSA-r8wq-qrxc-hmcm python-ldap (PyPI) Fixed in 3.4.0 Advisory →
Timeline
- 2026-10-03 Threatist record created from GHSA-r8wq-qrxc-hmcm
References
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences