PYSEC-2026-912

Vulnerability from pysec - Published: 2026-07-06 08:03 - Updated: 2026-07-07 11:31
VLAI
Details

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.

Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Impacted products
Name purl
python-ldap pkg:pypi/python-ldap
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "python-ldap",
        "purl": "pkg:pypi/python-ldap"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.4.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.3.13",
        "2.4.0",
        "2.4.1",
        "2.4.10",
        "2.4.12",
        "2.4.13",
        "2.4.14",
        "2.4.15",
        "2.4.16",
        "2.4.17",
        "2.4.18",
        "2.4.19",
        "2.4.2",
        "2.4.20",
        "2.4.21",
        "2.4.22",
        "2.4.25",
        "2.4.26",
        "2.4.27",
        "2.4.28",
        "2.4.29",
        "2.4.3",
        "2.4.30",
        "2.4.31",
        "2.4.32",
        "2.4.33",
        "2.4.35",
        "2.4.36",
        "2.4.37",
        "2.4.38",
        "2.4.39",
        "2.4.4",
        "2.4.40",
        "2.4.41",
        "2.4.42",
        "2.4.43",
        "2.4.44",
        "2.4.45",
        "2.4.5",
        "2.4.6",
        "2.4.7",
        "2.4.8",
        "2.4.9",
        "2.5.1",
        "2.5.2",
        "3.0.0",
        "3.0.0b1",
        "3.0.0b2",
        "3.0.0b3",
        "3.0.0b4",
        "3.1.0",
        "3.2.0",
        "3.3.0",
        "3.3.1"
      ]
    }
  ],
  "aliases": [
    "CVE-2021-46823",
    "GHSA-qfr5-wjpw-q4c4"
  ],
  "details": "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.",
  "id": "PYSEC-2026-912",
  "modified": "2026-07-07T11:31:03.877690Z",
  "published": "2026-07-06T08:03:30.875950Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-46823"
    },
    {
      "type": "WEB",
      "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/221507"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/python-ldap/python-ldap"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/python-ldap"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-qfr5-wjpw-q4c4"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Denial of Service in python-ldap"
}


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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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