CVE-2026-8365 (GCVE-0-2026-8365)
Vulnerability from cvelistv5 – Published: 2026-06-09 08:29 – Updated: 2026-06-09 12:56
VLAI
EPSS
VEX
Title
Blocksy <= 2.1.41 - Authenticated (Contributor+) PHP Object Injection via Deserialization of Untrusted Data via 'blocksy_meta' REST API Field
Summary
The Blocksy theme for WordPress is vulnerable to PHP Object Injection leading to Remote Code Execution via the 'blocksy_meta' REST API field and the V200 database migration in versions up to and including 2.1.35. This is due to insufficient input sanitization in the blocksy_sanitize_post_meta_options() function, which only blocks values containing '<' or '>' and does not prevent serialized PHP object strings from being stored in post meta, combined with the SearchReplacer::run_recursively() function unconditionally deserializing all string values via @unserialize() during migration without restricting allowed classes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject a serialized Blocksy\RaiiPattern object into post meta that, when the V200 migration runs on an upgraded site, is deserialized and triggers RaiiPattern::__destruct(), which executes arbitrary PHP callables via call_user_func().
Severity
8.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-09 12:55 UTC
CWE
- CWE-502 - Deserialization of Untrusted Data
Assigner
References
13 references
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| creativethemeshq | Blocksy |
Affected:
0 , ≤ 2.1.41
(semver)
|
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-8365",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-06-09T12:55:53.628058Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-06-09T12:56:15.813Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Blocksy",
"vendor": "creativethemeshq",
"versions": [
{
"lessThanOrEqual": "2.1.41",
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Qu\u1ed1c Huy"
}
],
"descriptions": [
{
"lang": "en",
"value": "The Blocksy theme for WordPress is vulnerable to PHP Object Injection leading to Remote Code Execution via the \u0027blocksy_meta\u0027 REST API field and the V200 database migration in versions up to and including 2.1.35. This is due to insufficient input sanitization in the blocksy_sanitize_post_meta_options() function, which only blocks values containing \u0027\u003c\u0027 or \u0027\u003e\u0027 and does not prevent serialized PHP object strings from being stored in post meta, combined with the SearchReplacer::run_recursively() function unconditionally deserializing all string values via @unserialize() during migration without restricting allowed classes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject a serialized Blocksy\\RaiiPattern object into post meta that, when the V200 migration runs on an upgraded site, is deserialized and triggers RaiiPattern::__destruct(), which executes arbitrary PHP callables via call_user_func()."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-502",
"description": "CWE-502 Deserialization of Untrusted Data",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-06-09T08:29:40.638Z",
"orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
"shortName": "Wordfence"
},
"references": [
{
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/fd216743-ce8d-4632-9fd1-d63502c2dfcd?source=cve"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/inc/classes/db-versioning/utils/db-search-replacer.php#L98"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/inc/classes/db-versioning/utils/db-search-replacer.php#L98"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/admin/helpers/meta-boxes.php#L104"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/admin/helpers/meta-boxes.php#L104"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/admin/helpers/validator.php#L75"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/admin/helpers/validator.php#L75"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/inc/classes/raii.php#L12"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/inc/classes/raii.php#L12"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/db-versioning/utils/db-search-replacer.php#L98"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/meta-boxes.php#L104"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/validator.php#L75"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/raii.php#L12"
}
],
"timeline": [
{
"lang": "en",
"time": "2026-05-12T06:30:57.000Z",
"value": "Vendor Notified"
},
{
"lang": "en",
"time": "2026-06-08T20:11:29.000Z",
"value": "Disclosed"
}
],
"title": "Blocksy \u003c= 2.1.41 - Authenticated (Contributor+) PHP Object Injection via Deserialization of Untrusted Data via \u0027blocksy_meta\u0027 REST API Field"
}
},
"cveMetadata": {
"assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
"assignerShortName": "Wordfence",
"cveId": "CVE-2026-8365",
"datePublished": "2026-06-09T08:29:40.638Z",
"dateReserved": "2026-05-11T19:25:24.123Z",
"dateUpdated": "2026-06-09T12:56:15.813Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-8365",
"date": "2026-11-14",
"epss": "0.01121",
"percentile": "0.66725"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Blocksy",
"vendor": "creativethemeshq",
"versions": [
{
"lessThanOrEqual": "2.1.41",
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"source": "security@wordfence.com"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "The Blocksy theme for WordPress is vulnerable to PHP Object Injection leading to Remote Code Execution via the \u0027blocksy_meta\u0027 REST API field and the V200 database migration in versions up to and including 2.1.35. This is due to insufficient input sanitization in the blocksy_sanitize_post_meta_options() function, which only blocks values containing \u0027\u003c\u0027 or \u0027\u003e\u0027 and does not prevent serialized PHP object strings from being stored in post meta, combined with the SearchReplacer::run_recursively() function unconditionally deserializing all string values via @unserialize() during migration without restricting allowed classes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject a serialized Blocksy\\RaiiPattern object into post meta that, when the V200 migration runs on an upgraded site, is deserialized and triggers RaiiPattern::__destruct(), which executes arbitrary PHP callables via call_user_func()."
},
{
"lang": "es",
"value": "El tema Blocksy para WordPress es vulnerable a la inyecci\u00f3n de objetos PHP que conduce a la ejecuci\u00f3n remota de c\u00f3digo a trav\u00e9s del campo de la API REST \u0027blocksy_meta\u0027 y la migraci\u00f3n de la base de datos V200 en versiones hasta la 2.1.35 inclusive. Esto se debe a una sanitizaci\u00f3n insuficiente de la entrada en la funci\u00f3n blocksy_sanitize_post_meta_options(), que solo bloquea valores que contienen \u0027\u003c\u0027 o \u0027\u003e\u0027 y no evita que las cadenas de objetos PHP serializados se almacenen en los metadatos de las publicaciones, combinado con la funci\u00f3n SearchReplacer::run_recursively() que deserializa incondicionalmente todos los valores de cadena a trav\u00e9s de @unserialize() durante la migraci\u00f3n sin restringir las clases permitidas. Esto hace posible que atacantes autenticados, con acceso de nivel de colaborador y superior, inyecten un objeto Blocksy\\RaiiPattern serializado en los metadatos de las publicaciones que, cuando la migraci\u00f3n V200 se ejecuta en un sitio actualizado, es deserializado y activa RaiiPattern::__destruct(), que ejecuta callables PHP arbitrarios a trav\u00e9s de call_user_func()."
}
],
"id": "CVE-2026-8365",
"lastModified": "2026-07-23T08:10:00.137",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.8,
"impactScore": 5.9,
"source": "security@wordfence.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-8365",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-06-09T12:55:53.628058Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-06-09T09:16:31.013",
"references": [
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/meta-boxes.php#L104"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/validator.php#L75"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/db-versioning/utils/db-search-replacer.php#L98"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/raii.php#L12"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/admin/helpers/meta-boxes.php#L104"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/admin/helpers/validator.php#L75"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/inc/classes/db-versioning/utils/db-search-replacer.php#L98"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/inc/classes/raii.php#L12"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/admin/helpers/meta-boxes.php#L104"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/admin/helpers/validator.php#L75"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/inc/classes/db-versioning/utils/db-search-replacer.php#L98"
},
{
"source": "security@wordfence.com",
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/inc/classes/raii.php#L12"
},
{
"source": "security@wordfence.com",
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/fd216743-ce8d-4632-9fd1-d63502c2dfcd?source=cve"
}
],
"sourceIdentifier": "security@wordfence.com",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-502"
}
],
"source": "security@wordfence.com",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"current_release_date": "2026-06-10T08:59:08+00:00",
"cve": "CVE-2026-8365",
"id": "CVE-2026-8365",
"initial_release_date": "2026-01-01T00:00:00+00:00",
"product_status:known_not_affected": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "Blocksy \u003c= 2.1.41 - Authenticated (Contributor+) PHP Object Injection via Deserialization of Untrusted Data via \u0027blocksy_meta\u0027 REST API Field",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8365.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-8365",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-06-09T12:55:53.628058Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-06-09T12:56:09.369Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Blocksy",
"vendor": "creativethemeshq",
"versions": [
{
"lessThanOrEqual": "2.1.41",
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Qu\u1ed1c Huy"
}
],
"descriptions": [
{
"lang": "en",
"value": "The Blocksy theme for WordPress is vulnerable to PHP Object Injection leading to Remote Code Execution via the \u0027blocksy_meta\u0027 REST API field and the V200 database migration in versions up to and including 2.1.35. This is due to insufficient input sanitization in the blocksy_sanitize_post_meta_options() function, which only blocks values containing \u0027\u003c\u0027 or \u0027\u003e\u0027 and does not prevent serialized PHP object strings from being stored in post meta, combined with the SearchReplacer::run_recursively() function unconditionally deserializing all string values via @unserialize() during migration without restricting allowed classes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject a serialized Blocksy\\RaiiPattern object into post meta that, when the V200 migration runs on an upgraded site, is deserialized and triggers RaiiPattern::__destruct(), which executes arbitrary PHP callables via call_user_func()."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-502",
"description": "CWE-502 Deserialization of Untrusted Data",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-06-09T08:29:40.638Z",
"orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
"shortName": "Wordfence"
},
"references": [
{
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/fd216743-ce8d-4632-9fd1-d63502c2dfcd?source=cve"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/inc/classes/db-versioning/utils/db-search-replacer.php#L98"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/inc/classes/db-versioning/utils/db-search-replacer.php#L98"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/admin/helpers/meta-boxes.php#L104"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/admin/helpers/meta-boxes.php#L104"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/admin/helpers/validator.php#L75"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/admin/helpers/validator.php#L75"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/trunk/inc/classes/raii.php#L12"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.41/inc/classes/raii.php#L12"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/db-versioning/utils/db-search-replacer.php#L98"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/meta-boxes.php#L104"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/admin/helpers/validator.php#L75"
},
{
"url": "https://themes.trac.wordpress.org/browser/blocksy/2.1.35/inc/classes/raii.php#L12"
}
],
"timeline": [
{
"lang": "en",
"time": "2026-05-12T06:30:57.000Z",
"value": "Vendor Notified"
},
{
"lang": "en",
"time": "2026-06-08T20:11:29.000Z",
"value": "Disclosed"
}
],
"title": "Blocksy \u003c= 2.1.41 - Authenticated (Contributor+) PHP Object Injection via Deserialization of Untrusted Data via \u0027blocksy_meta\u0027 REST API Field"
}
},
"cveMetadata": {
"assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
"assignerShortName": "Wordfence",
"cveId": "CVE-2026-8365",
"datePublished": "2026-06-09T08:29:40.638Z",
"dateReserved": "2026-05-11T19:25:24.123Z",
"dateUpdated": "2026-06-09T12:56:15.813Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
Loading…
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.