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MSRC_CVE-2026-86145

Vulnerability from csaf_microsoft - Published: 2026-09-06 04:37 - Updated: 2026-09-07 14:49
Summary
PCRE2 before 10.48 allows a pcre2_dfa_match out-of-bounds write because reuse of a cached workspace block, in a recursive DFA matching workspace, lacks a size check (even though a newly allocated block, for the same purpose, does have a size check). This outcome requires an attacker-controlled regular expression, or a recursive pattern in conjunction with a small heap limit (this can be set through the API).
Notes
Additional Resources: To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle
Disclaimer: The information provided in the Microsoft Knowledge Base is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
CWE-424 - Improper Protection of Alternate Path
Affected products
Product Identifier Version Remediation
Unresolved product id: 17084-1
None Available

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-86145 PCRE2 before 10.48 allows a pcre2_dfa_match out-of-bounds write because reuse of a cached workspace block, in a recursive DFA matching workspace, lacks a size check (even though a newly allocated block, for the same purpose, does have a size check). This outcome requires an attacker-controlled regular expression, or a recursive pattern in conjunction with a small heap limit (this can be set through the API). - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-86145.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "PCRE2 before 10.48 allows a pcre2_dfa_match out-of-bounds write because reuse of a cached workspace block, in a recursive DFA matching workspace, lacks a size check (even though a newly allocated block, for the same purpose, does have a size check). This outcome requires an attacker-controlled regular expression, or a recursive pattern in conjunction with a small heap limit (this can be set through the API).",
    "tracking": {
      "current_release_date": "2026-09-07T14:49:07.000Z",
      "generator": {
        "date": "2026-09-08T07:02:02.696Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-86145",
      "initial_release_date": "2026-09-06T04:37:22.000Z",
      "revision_history": [
        {
          "date": "2026-09-06T04:37:22.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2026-09-07T14:49:07.000Z",
          "legacy_version": "2",
          "number": "2",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "azl3 pcre2 0:10.42-3.azl3",
                "product": {
                  "name": "azl3 pcre2 0:10.42-3.azl3",
                  "product_id": "1"
                }
              }
            ],
            "category": "product_name",
            "name": "pcre2"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 pcre2 0:10.42-3.azl3 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-86145",
      "cwe": {
        "id": "CWE-424",
        "name": "Improper Protection of Alternate Path"
      },
      "notes": [
        {
          "category": "general",
          "text": "mitre",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "known_affected": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-86145 PCRE2 before 10.48 allows a pcre2_dfa_match out-of-bounds write because reuse of a cached workspace block, in a recursive DFA matching workspace, lacks a size check (even though a newly allocated block, for the same purpose, does have a size check). This outcome requires an attacker-controlled regular expression, or a recursive pattern in conjunction with a small heap limit (this can be set through the API). - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-86145.json"
        }
      ],
      "remediations": [
        {
          "category": "none_available",
          "date": "2026-09-06T04:37:22.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17084-1"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "temporalScore": 8.2,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L",
            "version": "3.1"
          },
          "products": [
            "17084-1"
          ]
        }
      ],
      "title": "PCRE2 before 10.48 allows a pcre2_dfa_match out-of-bounds write because reuse of a cached workspace block, in a recursive DFA matching workspace, lacks a size check (even though a newly allocated block, for the same purpose, does have a size check). This outcome requires an attacker-controlled regular expression, or a recursive pattern in conjunction with a small heap limit (this can be set through the API)."
    }
  ]
}



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