CVE-2026-108109

PHPNuxBill through 2025.3.20 contains an account takeover vulnerability in the customer password reset flow in system/controllers/forgot.php that allows unauthenticated attackers to brute-force the 6-digit otp_code. Attackers knowing a customer username can guess the code without attempt limits or lockout, then read the newly set password from the HTTP response to hijack the account.

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/hotspotbilling/phpnuxbill
https://github.com/hotspotbilling/phpnuxbill/blob/2025.3.13/system/controllers/forgot.php#L41
https://github.com/hotspotbilling/phpnuxbill/commit/c3c2a92d468af91136d747b75142ed72f10320cc
https://github.com/hotspotbilling/phpnuxbill/security/advisories/GHSA-337r-rrrc-r559
https://www.vulncheck.com/advisories/phpnuxbill-through-2025.3.20-account-takeover-via-brute-forceable-password-reset-code
https://github.com/hotspotbilling/phpnuxbill/security/advisories/GHSA-337r-rrrc-r559

Configurations

No configuration.

History

09 Oct 2026, 18:17

Type	Values Removed	Values Added
References	~~() https://github.com/hotspotbilling/phpnuxbill/security/advisories/GHSA-337r-rrrc-r559 -~~	() https://github.com/hotspotbilling/phpnuxbill/security/advisories/GHSA-337r-rrrc-r559 -

09 Oct 2026, 15:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-09 15:17

Updated : 2026-10-09 18:17

NVD link : CVE-2026-108109

Mitre link : CVE-2026-108109

CVE.ORG link : CVE-2026-108109

JSON object : View

Products Affected

No product.

CWE

CWE-307

Improper Restriction of Excessive Authentication Attempts

{"id": "CVE-2026-108109", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-108109", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-10-09T17:25:00.595911Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "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": "disclosure@vulncheck.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 9.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "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:X/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": "NOT_DEFINED", "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"}}]}, "affected": [{"source": "disclosure@vulncheck.com", "affectedData": [{"vendor": "hotspotbilling", "product": "phpnuxbill", "versions": [{"status": "affected", "version": "0", "versionType": "custom", "lessThanOrEqual": "2025.3.20"}], "defaultStatus": "unaffected"}]}], "published": "2026-10-09T15:17:12.047", "references": [{"url": "https://github.com/hotspotbilling/phpnuxbill", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/hotspotbilling/phpnuxbill/blob/2025.3.13/system/controllers/forgot.php#L41", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/hotspotbilling/phpnuxbill/commit/c3c2a92d468af91136d747b75142ed72f10320cc", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/hotspotbilling/phpnuxbill/security/advisories/GHSA-337r-rrrc-r559", "source": "disclosure@vulncheck.com"}, {"url": "https://www.vulncheck.com/advisories/phpnuxbill-through-2025.3.20-account-takeover-via-brute-forceable-password-reset-code", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/hotspotbilling/phpnuxbill/security/advisories/GHSA-337r-rrrc-r559", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "description": [{"lang": "en", "value": "CWE-307"}]}], "descriptions": [{"lang": "en", "value": "PHPNuxBill through 2025.3.20 contains an account takeover vulnerability in the customer password reset flow in system/controllers/forgot.php that allows unauthenticated attackers to brute-force the 6-digit otp_code. Attackers knowing a customer username can guess the code without attempt limits or lockout, then read the newly set password from the HTTP response to hijack the account."}], "lastModified": "2026-10-09T18:17:06.727", "sourceIdentifier": "disclosure@vulncheck.com"}