Vulnerability-Lookup

GHSA-23W6-3W8W-8484

Vulnerability from github – Published: 2026-09-01 21:28 – Updated: 2026-09-01 21:28

Summary

pypdf: Possible long runtimes/large memory usage when retrieving outlines

Details

Impact

An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires accessing the outlines of a document with either lots of entries or nested outlines with long re-used nesting paths.

Patches

This has been fixed in pypdf==6.16.1.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #3966.

Severity

4.8 (Medium)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "pypdf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.16.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-84310"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-405",
      "CWE-834"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-01T21:28:37Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nAn attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires accessing the outlines of a document with either lots of entries or nested outlines with long re-used nesting paths.\n\n### Patches\n\nThis has been fixed in [pypdf==6.16.1](https://github.com/py-pdf/pypdf/releases/tag/6.16.1).\n\n### Workarounds\n\nIf you cannot upgrade yet, consider applying the changes from PR [#3966](https://github.com/py-pdf/pypdf/pull/3966).",
  "id": "GHSA-23w6-3w8w-8484",
  "modified": "2026-09-01T21:28:38Z",
  "published": "2026-09-01T21:28:37Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-23w6-3w8w-8484"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/pull/3966"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/py-pdf/pypdf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/releases/tag/6.16.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "pypdf: Possible long runtimes/large memory usage when retrieving outlines"
}

CVE-2026-84310 (GCVE-0-2026-84310)

Vulnerability from cvelistv5 – Published: 2026-09-01 20:00 – Updated: 2026-09-04 02:07

Title

pypdf: Possible long runtimes/large memory usage when retrieving outlines

Summary

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_doc_common.py _get_outline to consume long runtimes and large amounts of memory when retrieving document outlines with large numbers of entries or deeply nested reused paths because the traversal lacked global entry-count and nesting-depth limits. This issue is fixed in version 6.16.1.

Severity

4.8 (Medium)


                        
                          CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-04 02:07 UTC

CWE

CWE-405 - Asymmetric Resource Consumption (Amplification)
CWE-834 - Excessive Iteration

Assigner

GitHub_M mitre root

References

4 references

URL	Tags
https://github.com/py-pdf/pypdf/security/advisori…	x_refsource_CONFIRM
https://github.com/py-pdf/pypdf/pull/3966	x_refsource_MISC
https://github.com/py-pdf/pypdf/commit/d91ab705fd…	x_refsource_MISC
https://github.com/py-pdf/pypdf/releases/tag/6.16.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
py-pdf	pypdf	Affected: < 6.16.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-84310",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-04T02:07:38.724444Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-04T02:07:48.971Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "pypdf",
          "vendor": "py-pdf",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.16.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_doc_common.py _get_outline to consume long runtimes and large amounts of memory when retrieving document outlines with large numbers of entries or deeply nested reused paths because the traversal lacked global entry-count and nesting-depth limits. This issue is fixed in version 6.16.1."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "LOCAL",
            "baseScore": 4.8,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-405",
              "description": "CWE-405: Asymmetric Resource Consumption (Amplification)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-834",
              "description": "CWE-834: Excessive Iteration",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-01T20:00:59.455Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-23w6-3w8w-8484",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-23w6-3w8w-8484"
        },
        {
          "name": "https://github.com/py-pdf/pypdf/pull/3966",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/py-pdf/pypdf/pull/3966"
        },
        {
          "name": "https://github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942"
        },
        {
          "name": "https://github.com/py-pdf/pypdf/releases/tag/6.16.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/py-pdf/pypdf/releases/tag/6.16.1"
        }
      ],
      "source": {
        "advisory": "GHSA-23w6-3w8w-8484",
        "discovery": "UNKNOWN"
      },
      "title": "pypdf: Possible long runtimes/large memory usage when retrieving outlines"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-84310",
    "datePublished": "2026-09-01T20:00:59.455Z",
    "dateReserved": "2026-09-01T16:17:43.079Z",
    "dateUpdated": "2026-09-04T02:07:48.971Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.