FKIE_CVE-2026-40495
Vulnerability from fkie_nvd - Published: 2026-06-03 20:16 - Updated: 2026-07-22 20:10
Severity
Summary
FOSSBilling is a free, open-source billing and client management system. Versions prior to 0.8.0 leak the exact system version through asset cache buster parameters in HTML output, bypassing the `hide_version_public` security setting. The FOSSBilling version is embedded in the query string of every `<script>` and `<link>` tag generated by the `script_tag` and `stylesheet_tag` Twig filters. This information is visible to all visitors — including unauthenticated guests — on every page, regardless of whether the `hide_version_public` setting is enabled. The `X-FOSSBilling-Version` HTTP header and the `guest.system.version` API endpoint correctly honour the `hide_version_public` setting, but the asset cache buster parameters were overlooked. Knowledge of the exact FOSSBilling version makes it significantly easier for malicious actors to identify known vulnerabilities applicable to a given installation and craft targeted exploits. While not a direct vulnerability on its own, it undermines the intended protection offered by the `hide_version_public` setting and facilitates reconnaissance. Version 0.8.0 contains a patch. There is no practical workaround that removes the version from asset URLs without modifying source code.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"product": "FOSSBilling",
"vendor": "FOSSBilling",
"versions": [
{
"status": "affected",
"version": "\u003c 0.8.0"
}
]
}
],
"source": "security-advisories@github.com"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "FOSSBilling is a free, open-source billing and client management system. Versions prior to 0.8.0 leak the exact system version through asset cache buster parameters in HTML output, bypassing the `hide_version_public` security setting. The FOSSBilling version is embedded in the query string of every `\u003cscript\u003e` and `\u003clink\u003e` tag generated by the `script_tag` and `stylesheet_tag` Twig filters. This information is visible to all visitors \u2014 including unauthenticated guests \u2014 on every page, regardless of whether the `hide_version_public` setting is enabled. The `X-FOSSBilling-Version` HTTP header and the `guest.system.version` API endpoint correctly honour the `hide_version_public` setting, but the asset cache buster parameters were overlooked. Knowledge of the exact FOSSBilling version makes it significantly easier for malicious actors to identify known vulnerabilities applicable to a given installation and craft targeted exploits. While not a direct vulnerability on its own, it undermines the intended protection offered by the `hide_version_public` setting and facilitates reconnaissance. Version 0.8.0 contains a patch. There is no practical workaround that removes the version from asset URLs without modifying source code."
},
{
"lang": "es",
"value": "FOSSBilling es un sistema de facturaci\u00f3n y gesti\u00f3n de clientes gratuito y de c\u00f3digo abierto. Las versiones anteriores a la 0.8.0 filtran la versi\u00f3n exacta del sistema a trav\u00e9s de par\u00e1metros de cache buster de activos en la salida HTML, eludiendo la configuraci\u00f3n de seguridad hide_version_public . La versi\u00f3n de FOSSBilling est\u00e1 incrustada en la cadena de consulta de cada etiqueta \u0027 script \u0027 y \u0027 link \u0027 generada por los filtros Twig script_tag y stylesheet_tag . Esta informaci\u00f3n es visible para todos los visitantes -incluidos los invitados no autenticados- en cada p\u00e1gina, independientemente de si la configuraci\u00f3n hide_version_public est\u00e1 habilitada. El encabezado HTTP X-FOSSBilling-Version y el endpoint API guest.system.version respetan correctamente la configuraci\u00f3n hide_version_public , pero los par\u00e1metros de cache buster de activos fueron pasados por alto. El conocimiento de la versi\u00f3n exacta de FOSSBilling facilita significativamente a los actores maliciosos identificar vulnerabilidades conocidas aplicables a una instalaci\u00f3n determinada y elaborar exploits dirigidos. Aunque no es una vulnerabilidad directa por s\u00ed misma, socava la protecci\u00f3n prevista ofrecida por la configuraci\u00f3n hide_version_public y facilita el reconocimiento. La versi\u00f3n 0.8.0 contiene un parche. No existe una soluci\u00f3n alternativa pr\u00e1ctica que elimine la versi\u00f3n de las URL de los activos sin modificar el c\u00f3digo fuente."
}
],
"id": "CVE-2026-40495",
"lastModified": "2026-07-22T20:10:00.127",
"metrics": {
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 6.9,
"baseSeverity": "MEDIUM",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/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",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "LOW",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "security-advisories@github.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-40495",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-06-04T13:49:19.491304Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-06-03T20:16:20.333",
"references": [
{
"source": "security-advisories@github.com",
"url": "https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.0"
},
{
"source": "security-advisories@github.com",
"url": "https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-gqcp-g7rm-p5v6"
}
],
"sourceIdentifier": "security-advisories@github.com",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-200"
}
],
"source": "security-advisories@github.com",
"type": "Secondary"
}
]
}
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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.
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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.
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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.
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