CVE-2026-42608

Grav is a file-based Web platform. Prior to 2.0.0-beta.2, there is a Path Traversal vulnerability within the FormFlash core component. By manipulating the session_id (passed as __form-flash-id in POST requests), an unauthenticated attacker can traverse the filesystem to create arbitrary directories and write an index.yaml file containing attacker-controlled data. This vulnerability can lead to unauthorized modification of application behavior, potential data integrity issues, and service disruption in production environments. This vulnerability is fixed in 2.0.0-beta.2.

CVSS v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2	Exploit Vendor Advisory
https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:getgrav:grav::::::::
	cpe:2.3:a:getgrav:grav:2.0.0:beta1::::::

History

13 May 2026, 18:39

Type	Values Removed	Values Added
References	~~() https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2 -~~	() https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2 - Exploit, Vendor Advisory
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.1
First Time		Getgrav grav Getgrav
CPE		cpe:2.3:a:getgrav:grav:::::::: cpe:2.3:a:getgrav:grav:2.0.0:beta1::::::

11 May 2026, 17:16

Type	Values Removed	Values Added
References	~~() https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2 -~~	() https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2 -

11 May 2026, 16:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-11 16:17

Updated : 2026-05-13 18:39

NVD link : CVE-2026-42608

Mitre link : CVE-2026-42608

CVE.ORG link : CVE-2026-42608

JSON object : View

Products Affected

getgrav

grav

CWE

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

{"id": "CVE-2026-42608", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.8, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "PROOF_OF_CONCEPT", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "published": "2026-05-11T16:17:33.207", "references": [{"url": "https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-22"}]}], "descriptions": [{"lang": "en", "value": "Grav is a file-based Web platform. Prior to 2.0.0-beta.2, there is a Path Traversal vulnerability within the FormFlash core component. By manipulating the session_id (passed as __form-flash-id in POST requests), an unauthenticated attacker can traverse the filesystem to create arbitrary directories and write an index.yaml file containing attacker-controlled data. This vulnerability can lead to unauthorized modification of application behavior, potential data integrity issues, and service disruption in production environments. This vulnerability is fixed in 2.0.0-beta.2."}], "lastModified": "2026-05-13T18:39:05.060", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "064CDB77-36FA-4294-9397-0D6FC8E67F1F", "versionEndExcluding": "2.0.0"}, {"criteria": "cpe:2.3:a:getgrav:grav:2.0.0:beta1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1ABB323F-20AF-40F3-BCD9-262644D242A1"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}