CVE-2026-13713 (GCVE-0-2026-13713)
Vulnerability from cvelistv5 – Published: 2026-07-16 21:35 – Updated: 2026-07-17 13:18
VLAI
EPSS
VEX
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)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-17 13:17 UTC
Assigner
References
3 references
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| TODDR | YAML::Syck |
Affected:
0 , < 1.47
(custom)
|
guessed |
{
"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": "2026-09-21",
"epss": "0.00134",
"percentile": "0.03266"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"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"
}
]
}
],
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
}
],
"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."
}
],
"id": "CVE-2026-13713",
"lastModified": "2026-07-17T15:07:41.947",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"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"
},
"exploitabilityScore": 2.5,
"impactScore": 3.6,
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-13713",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-17T13:17:36.382946Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-07-16T22:16:59.640",
"references": [
{
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"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": "af854a3a-2127-422b-91ae-364da2661108",
"url": "http://www.openwall.com/lists/oss-security/2026/07/17/1"
}
],
"sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-415"
},
{
"lang": "en",
"value": "CWE-416"
}
],
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Important",
"current_release_date": "2026-09-14T09:06:37+00:00",
"cve": "CVE-2026-13713",
"id": "CVE-2026-13713",
"initial_release_date": "2026-07-16T21:35:31.477000+00:00",
"product_status:fixed": "13",
"product_status:known_affected": "3",
"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"
},
"suse_vex": {
"aggregate_severity": "moderate",
"current_release_date": "2026-07-19T17:43:55Z",
"cve": "CVE-2026-13713",
"id": "CVE-2026-13713",
"initial_release_date": "2026-07-17T13:00:50Z",
"product_status:recommended": "1",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-13713",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-13713.json",
"version": "3"
},
"vulnrichment": {
"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": "2026-07-17T13:17:58.545Z",
"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"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
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.
Loading…
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.
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.
Loading…
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.
Loading…