CVE-2026-27810

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{"affected": [{"affectedData": [{"product": "calibre", "vendor": "kovidgoyal", "versions": [{"status": "affected", "version": "< 9.4.0"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:calibre-ebook:calibre:*:*:*:*:*:*:*:*", "matchCriteriaId": "3665E54E-5F8D-405A-BA97-8DD783962094", "versionEndExcluding": "9.4.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.4.0, an HTTP Response Header Injection vulnerability in the calibre Content Server allows any authenticated user to inject arbitrary HTTP headers into server responses via an unsanitized `content_disposition` query parameter in the `/get/` and `/data-files/get/` endpoints. All users running the calibre Content Server with authentication enabled are affected. The vulnerability is exploitable by any authenticated user and can also be triggered by tricking an authenticated victim into clicking a crafted link. Version 9.4.0 contains a fix for the issue."}, {"lang": "es", "value": "calibre es un gestor de libros electr\u00f3nicos multiplataforma para ver, convertir, editar y catalogar libros electr\u00f3nicos. Antes de la versi\u00f3n 9.4.0, una vulnerabilidad de inyecci\u00f3n de encabezado de respuesta HTTP en el servidor de contenido de calibre permite a cualquier usuario autenticado inyectar encabezados HTTP arbitrarios en las respuestas del servidor a trav\u00e9s de un par\u00e1metro de consulta 'content_disposition' no saneado en los puntos finales '/get/' y '/data-files/get/'. Todos los usuarios que ejecutan el servidor de contenido de calibre con la autenticaci\u00f3n habilitada se ven afectados. La vulnerabilidad es explotable por cualquier usuario autenticado y tambi\u00e9n puede ser activada enga\u00f1ando a una v\u00edctima autenticada para que haga clic en un enlace manipulado. La versi\u00f3n 9.4.0 contiene una soluci\u00f3n para el problema."}], "id": "CVE-2026-27810", "lastModified": "2026-06-17T10:27:43.377", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 3.1, "impactScore": 2.7, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 3.1, "impactScore": 2.7, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-27810", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-03-02T12:53:21.102653Z", "version": "2.0.3"}}]}, "published": "2026-02-27T20:21:39.780", "references": [{"source": "security-advisories@github.com", "tags": ["Exploit", "Mitigation", "Vendor Advisory"], "url": "https://github.com/kovidgoyal/calibre/security/advisories/GHSA-5fpj-fxw7-8grw"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-113"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,9.4.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "calibre", "source": "cna", "vendor": "kovidgoyal"}, "product": "calibre", "vendor": "kovidgoyal"}], "analysis": {"en": {"generated_at": "2026-04-18T19:33:49.100323+00:00", "value": {"mitigation_remediation": ["Upgrade calibre to version\u202f9.4.0 or later", "If upgrading is not feasible, configure the Content Server (or web server proxy) to reject or strip the content_disposition query parameter from the /get/ and /data-files/get/ endpoints, thereby preventing header injection", "Disable or protect the Content Server endpoints by applying stricter authentication controls or by removing public access to the /get/ and /data-files/get/ URLs"], "summary": {"action": "Apply Patch", "impact": "HTTP Response Header Injection"}, "threat_synthesis": {"affected_systems": "All users running calibre Content Server versions earlier than 9.4.0 with authentication enabled are affected. The vulnerability applies to every installation of the content server that exposes the default \"content_disposition\" parameter and has any form of user authentication configured. These deployments are produced by the vendor kovidgoyal and use the product calibre.", "description_and_impact": "A flaw in the calibre Content Server allows an authenticated user to inject arbitrary HTTP response headers through an unsanitized content_disposition query parameter on the /get/ and /data-files/get/ endpoints. This can lead to HTTP header manipulation, potentially compromising the integrity of responses. The weakness is categorized as CWE\u2011113. The issue can be triggered by an authenticated victim clicking a crafted link, making it potentially exploitable in victim\u2011based scenarios.", "risk_and_exploitability": "The vulnerability has a CVSS v3.1 score of 6.4, indicating a moderate severity. Current EPSS data shows an exploitation probability of less than 1\u202f%, suggesting a low likelihood of broad exploitation. The vulnerability is not listed in the CISA KEV catalog. Exploitation requires an authenticated session and manipulation of the content_disposition parameter, which can be achieved via a crafted URL."}}}}, "created": "2026-03-02T12:05:06.408416+00:00", "updated": "2026-04-18T19:45:08.957397+00:00", "vendors": ["kovidgoyal", "kovidgoyal$PRODUCT$calibre"]}