CVE-2026-13713 (GCVE-0-2026-13713)

Vulnerability from cvelistv5 – Published: 2026-07-16 21:35 – Updated: 2026-07-17 13:18
VLAI
Title
YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack
Summary
YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack. In the bundled libsyck, when an anchor name is redefined or removed, syck_hdlr_add_anchor and syck_hdlr_remove_anchor free the node stored under that name with syck_free_node. That node can still be live on the parser's value stack, so syck_hdlr_add_node reaches it again and frees it a second time. On a normal build the 48-byte node chunk is freed twice and the interpreter aborts. Anchors need no special flags, so this is reached on the default Load path, and a 7-byte document that redefines an anchor triggers it. Any caller that runs Load or LoadFile on an untrusted document that redefines an anchor mid-parse crashes the interpreter, a denial of service.
Severity
6.2 (Medium)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
Assigner
References
Impacted products
Vendor Product Version
TODDR YAML::Syck Affected: 0 , < 1.47 (custom)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-07-17T03:02:25.421Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/07/17/1"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 6.2,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-13713",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-17T13:17:36.382946Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-17T13:18:02.930Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "packageName": "YAML-Syck",
          "product": "YAML::Syck",
          "programFiles": [
            "handler.c",
            "syck_.c",
            "syck.h"
          ],
          "programRoutines": [
            {
              "name": "syck_hdlr_add_anchor"
            },
            {
              "name": "syck_hdlr_remove_anchor"
            },
            {
              "name": "syck_hdlr_add_node"
            }
          ],
          "repo": "https://github.com/toddr/YAML-Syck",
          "vendor": "TODDR",
          "versions": [
            {
              "lessThan": "1.47",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack.\n\nIn the bundled libsyck, when an anchor name is redefined or removed, syck_hdlr_add_anchor and syck_hdlr_remove_anchor free the node stored under that name with syck_free_node. That node can still be live on the parser\u0027s value stack, so syck_hdlr_add_node reaches it again and frees it a second time. On a normal build the 48-byte node chunk is freed twice and the interpreter aborts. Anchors need no special flags, so this is reached on the default Load path, and a 7-byte document that redefines an anchor triggers it.\n\nAny caller that runs Load or LoadFile on an untrusted document that redefines an anchor mid-parse crashes the interpreter, a denial of service."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-416",
              "description": "CWE-416 Use After Free",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-415",
              "description": "CWE-415 Double Free",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-16T21:35:31.477Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/TODDR/YAML-Syck-1.47/changes"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/toddr/YAML-Syck/commit/44c90a109ec3215ee7ce747bd11209835e123d8b.patch"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to YAML-Syck 1.47 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-13713",
    "datePublished": "2026-07-16T21:35:31.477Z",
    "dateReserved": "2026-06-29T13:57:19.498Z",
    "dateUpdated": "2026-07-17T13:18:02.930Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-13713",
      "date": "2026-07-17",
      "epss": "0.00186",
      "percentile": "0.08354"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-13713\",\"sourceIdentifier\":\"9b29abf9-4ab0-4765-b253-1875cd9b441e\",\"published\":\"2026-07-16T22:16:59.640\",\"lastModified\":\"2026-07-17T15:07:41.947\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack.\\n\\nIn the bundled libsyck, when an anchor name is redefined or removed, syck_hdlr_add_anchor and syck_hdlr_remove_anchor free the node stored under that name with syck_free_node. That node can still be live on the parser\u0027s value stack, so syck_hdlr_add_node reaches it again and frees it a second time. On a normal build the 48-byte node chunk is freed twice and the interpreter aborts. Anchors need no special flags, so this is reached on the default Load path, and a 7-byte document that redefines an anchor triggers it.\\n\\nAny caller that runs Load or LoadFile on an untrusted document that redefines an anchor mid-parse crashes the interpreter, a denial of service.\"}],\"affected\":[{\"source\":\"9b29abf9-4ab0-4765-b253-1875cd9b441e\",\"affectedData\":[{\"vendor\":\"TODDR\",\"product\":\"YAML::Syck\",\"defaultStatus\":\"unaffected\",\"collectionURL\":\"https://cpan.org/modules\",\"packageName\":\"YAML-Syck\",\"programFiles\":[\"handler.c\",\"syck_.c\",\"syck.h\"],\"programRoutines\":[{\"name\":\"syck_hdlr_add_anchor\"},{\"name\":\"syck_hdlr_remove_anchor\"},{\"name\":\"syck_hdlr_add_node\"}],\"repo\":\"https://github.com/toddr/YAML-Syck\",\"versions\":[{\"version\":\"0\",\"lessThan\":\"1.47\",\"versionType\":\"custom\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":6.2,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.5,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-17T13:17:36.382946Z\",\"id\":\"CVE-2026-13713\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"9b29abf9-4ab0-4765-b253-1875cd9b441e\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-415\"},{\"lang\":\"en\",\"value\":\"CWE-416\"}]}],\"references\":[{\"url\":\"https://github.com/toddr/YAML-Syck/commit/44c90a109ec3215ee7ce747bd11209835e123d8b.patch\",\"source\":\"9b29abf9-4ab0-4765-b253-1875cd9b441e\"},{\"url\":\"https://metacpan.org/release/TODDR/YAML-Syck-1.47/changes\",\"source\":\"9b29abf9-4ab0-4765-b253-1875cd9b441e\"},{\"url\":\"http://www.openwall.com/lists/oss-security/2026/07/17/1\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-07-17T14:05:02+00:00",
      "cve": "CVE-2026-13713",
      "id": "CVE-2026-13713",
      "initial_release_date": "2026-07-16T21:35:31.477000+00:00",
      "product_status:known_affected": "5",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "YAML-Syck: YAML::Syck: Denial of Service via crafted YAML document",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-13713.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"http://www.openwall.com/lists/oss-security/2026/07/17/1\"}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2026-07-17T03:02:25.421Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 6.2, \"attackVector\": \"LOCAL\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-13713\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-17T13:17:36.382946Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-17T13:17:58.545Z\"}}], \"cna\": {\"title\": \"YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack\", \"source\": {\"discovery\": \"UNKNOWN\"}, \"affected\": [{\"repo\": \"https://github.com/toddr/YAML-Syck\", \"vendor\": \"TODDR\", \"product\": \"YAML::Syck\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"1.47\", \"versionType\": \"custom\"}], \"packageName\": \"YAML-Syck\", \"programFiles\": [\"handler.c\", \"syck_.c\", \"syck.h\"], \"collectionURL\": \"https://cpan.org/modules\", \"defaultStatus\": \"unaffected\", \"programRoutines\": [{\"name\": \"syck_hdlr_add_anchor\"}, {\"name\": \"syck_hdlr_remove_anchor\"}, {\"name\": \"syck_hdlr_add_node\"}]}], \"solutions\": [{\"lang\": \"en\", \"value\": \"Upgrade to YAML-Syck 1.47 or later.\"}], \"references\": [{\"url\": \"https://metacpan.org/release/TODDR/YAML-Syck-1.47/changes\", \"tags\": [\"release-notes\"]}, {\"url\": \"https://github.com/toddr/YAML-Syck/commit/44c90a109ec3215ee7ce747bd11209835e123d8b.patch\", \"tags\": [\"patch\"]}], \"x_generator\": {\"engine\": \"cpansec-cna-tool 0.1\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack.\\n\\nIn the bundled libsyck, when an anchor name is redefined or removed, syck_hdlr_add_anchor and syck_hdlr_remove_anchor free the node stored under that name with syck_free_node. That node can still be live on the parser\u0027s value stack, so syck_hdlr_add_node reaches it again and frees it a second time. On a normal build the 48-byte node chunk is freed twice and the interpreter aborts. Anchors need no special flags, so this is reached on the default Load path, and a 7-byte document that redefines an anchor triggers it.\\n\\nAny caller that runs Load or LoadFile on an untrusted document that redefines an anchor mid-parse crashes the interpreter, a denial of service.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-416\", \"description\": \"CWE-416 Use After Free\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-415\", \"description\": \"CWE-415 Double Free\"}]}], \"providerMetadata\": {\"orgId\": \"9b29abf9-4ab0-4765-b253-1875cd9b441e\", \"shortName\": \"CPANSec\", \"dateUpdated\": \"2026-07-16T21:35:31.477Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-13713\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-17T13:18:02.930Z\", \"dateReserved\": \"2026-06-29T13:57:19.498Z\", \"assignerOrgId\": \"9b29abf9-4ab0-4765-b253-1875cd9b441e\", \"datePublished\": \"2026-07-16T21:35:31.477Z\", \"assignerShortName\": \"CPANSec\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.