Vulnerability-Lookup

BREW-GLIBC-CVE-2026-5450 (CVE-2026-5450)

Vulnerability from osv_homebrew – Published: 2026-08-05 16:54 – Updated: 2026-08-05 16:54 – Source website

Summary

scanf %mc off-by-one heap buffer overflow

Details

Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.

Severity

9.8 (Critical)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

URL

Type

	https://cert-portal.siemens.com/productcert/html/…	WEB
	https://github.com/CVEProject/cvelistV5/tree/main…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2026-5450	ADVISORY
	https://sourceware.org/bugzilla/show_bug.cgi?id=C…	REPORT
	https://inbox.sourceware.org/libc-announce/b11f00…	ARTICLE

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "patch",
        "patches": [
          {
            "apply": [
              "patches/any/CVE-2024-2961.patch",
              "patches/any/CVE-2024-33599.patch",
              "patches/any/CVE-2024-33600_1.patch",
              "patches/any/CVE-2024-33600_2.patch",
              "patches/any/CVE-2024-33601_33602.patch",
              "patches/any/CVE-2025-0395.patch",
              "patches/any/CVE-2025-5702.patch",
              "patches/any/CVE-2025-8058.patch",
              "patches/CVE-2025-15281.patch",
              "patches/CVE-2026-0861.patch",
              "patches/CVE-2026-0915.patch",
              "patches/CVE-2026-4046.patch",
              "patches/CVE-2026-5450.patch",
              "patches/CVE-2026-5928.patch",
              "patches/CVE-2026-6238-pre1.patch",
              "patches/CVE-2026-6238-pre2.patch",
              "patches/CVE-2026-6238-pre3.patch",
              "patches/CVE-2026-6238-pre4.patch",
              "patches/CVE-2026-5435.patch",
              "patches/CVE-2026-6238-1.patch",
              "patches/CVE-2026-6238-2.patch",
              "patches/CVE-2026-443x.patch"
            ],
            "type": "backport",
            "url": "https://archive.ubuntu.com/ubuntu/pool/main/g/glibc/glibc_2.39-0ubuntu8.8.debian.tar.xz"
          }
        ]
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "glibc",
        "purl": "pkg:brew/glibc"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.39_1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "source": "generated"
  },
  "details": "Calling the scanf family of functions with a %mc (malloc\u0027d character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.",
  "id": "BREW-glibc-CVE-2026-5450",
  "modified": "2026-08-05T16:54:10Z",
  "published": "2026-08-05T16:54:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5450.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-5450"
    },
    {
      "type": "REPORT",
      "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450"
    },
    {
      "type": "ARTICLE",
      "url": "https://inbox.sourceware.org/libc-announce/b11f0003-6ec1-4bd6-b9de-9e38a4efeca3@redhat.com/T/#u"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "scanf %mc off-by-one heap buffer overflow",
  "upstream": [
    "CVE-2026-5450"
  ]
}

CVE-2026-5450 (GCVE-0-2026-5450)

Vulnerability from cvelistv5 – Published: 2026-04-20 20:55 – Updated: 2026-10-15 01:12

Title

scanf %mc off-by-one heap buffer overflow

Summary

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-21 16:11 UTC

CWE

CWE-122 - Heap-based buffer overflow

Assigner

glibc CNA under the redhat root

CNA scorecard B 76/100 over 14 records in the last 180 days details

References

3 references

URL	Tags
https://sourceware.org/bugzilla/show_bug.cgi?id=C…	issue-tracking
https://inbox.sourceware.org/libc-announce/b11f00…	mailing-list
https://cert-portal.siemens.com/productcert/html/…

Impacted products

4 products

Vendor	Product	Version
The GNU C Library	glibc	Affected: 2.7 , < * (custom)
Siemens	SIMATIC S7-1500 CPU 1518-4 PN/DP MFP	Affected: V3.1.5 , < V3.1.6 (custom)
Siemens	SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP	Affected: V3.1.5 , < V3.1.6 (custom)
Siemens	SIPLUS S7-1500 CPU 1518-4 PN/DP MFP	Affected: V3.1.5 , < V3.1.6 (custom)

Date Public

2026-03-19 17:36

Credits

Rocket Ma

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.8,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-5450",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-21T16:11:50.875542Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-21T19:49:53.221Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      },
      {
        "affected": [
          {
            "defaultStatus": "unknown",
            "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
            "vendor": "Siemens",
            "versions": [
              {
                "lessThan": "V3.1.6",
                "status": "affected",
                "version": "V3.1.5",
                "versionType": "custom"
              }
            ]
          },
          {
            "defaultStatus": "unknown",
            "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
            "vendor": "Siemens",
            "versions": [
              {
                "lessThan": "V3.1.6",
                "status": "affected",
                "version": "V3.1.5",
                "versionType": "custom"
              }
            ]
          },
          {
            "defaultStatus": "unknown",
            "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
            "vendor": "Siemens",
            "versions": [
              {
                "lessThan": "V3.1.6",
                "status": "affected",
                "version": "V3.1.5",
                "versionType": "custom"
              }
            ]
          },
          {
            "defaultStatus": "unknown",
            "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
            "vendor": "Siemens",
            "versions": [
              {
                "lessThan": "V3.1.6",
                "status": "affected",
                "version": "V3.1.5",
                "versionType": "custom"
              }
            ]
          },
          {
            "defaultStatus": "unknown",
            "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
            "vendor": "Siemens",
            "versions": [
              {
                "lessThan": "V3.1.6",
                "status": "affected",
                "version": "V3.1.5",
                "versionType": "custom"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-15T01:12:13.391Z",
          "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
          "shortName": "siemens-SADP"
        },
        "references": [
          {
            "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"
          }
        ],
        "x_adpType": "supplier"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "glibc",
          "vendor": "The GNU C Library",
          "versions": [
            {
              "lessThan": "*",
              "status": "affected",
              "version": "2.7",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Rocket Ma"
        }
      ],
      "datePublic": "2026-03-19T17:36:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Calling the scanf family of functions with a %mc (malloc\u0027d character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow."
            }
          ],
          "value": "Calling the scanf family of functions with a %mc (malloc\u0027d character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-100",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-100 Overflow Buffers"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-122",
              "description": "CWE-122 Heap-based buffer overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-20T20:55:41.170Z",
        "orgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
        "shortName": "glibc"
      },
      "references": [
        {
          "tags": [
            "issue-tracking"
          ],
          "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450"
        },
        {
          "tags": [
            "mailing-list"
          ],
          "url": "https://inbox.sourceware.org/libc-announce/b11f0003-6ec1-4bd6-b9de-9e38a4efeca3@redhat.com/T/#u"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "scanf %mc off-by-one heap buffer overflow",
      "x_generator": {
        "engine": "Vulnogram 1.0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
    "assignerShortName": "glibc",
    "cveId": "CVE-2026-5450",
    "datePublished": "2026-04-20T20:55:41.170Z",
    "dateReserved": "2026-04-02T21:47:21.403Z",
    "dateUpdated": "2026-10-15T01:12:13.391Z",
    "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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted