CVE-2023-35173
MediumCVSS 5.7Exploitation Probability (EPSS)
Low risk31th percentile - higher than 31% of all known CVEs
Summary
The Nextcloud End-to-end encryption app provides the ability to implement end-to-end encryption on the client side. By providing an invalid metadata file, an attacker can make previously dropped files inaccessible.
Risk Assessment
The organization may lose access to important data, which can lead to serious operational and legal consequences.
Recommendation
It is recommended to upgrade the Nextcloud End-to-end encryption app to version 1.12.4 that contains the fix.
Related vulnerabilities
- CVE-2026-101283Critical
iperf3 3.20–3.21 (esnet/iperf) has a pre-auth heap buffer overflow in decrypt_rsa_message(): a 256-byte RSA buffer is BIO_read with the attacker-controlled ciphertext length (guard warns only), so an unauthenticated client overflows the heap via an oversized authtoken; fixed in 3.22
- CVE-2026-102149Critical
Kiteworks Email Protection Gateway did not sufficiently restrict which account a certificate could be assigned to. This could allow an attacker to associate a certificate with another user's account, affecting the confidentiality and integrity of that account's encrypted mail and, where certificate-based login is enabled, potentially permitting unauthorized access to the account.
- CVE-2026-102147Critical
A stored cross-site scripting (XSS) weakness in Kiteworks Core could allow an unauthenticated attacker to store crafted content that later executes arbitrary JavaScript in the authenticated session of an administrator who views the affected page. This could have permitted the attacker to gain full administrative control, including the creation of a new administrative account.
- CVE-2026-102115Critical
Kiteworks Core did not correctly validate a parameter submitted to the password reset workflow. An unauthenticated attacker who knew the email address of a user with a locally stored password could potentially reset that account's password without access to the emailed reset link and then authenticate as that user, including where the account holds administrative privileges.
- CVE-2026-102106Critical
Improper authentication in a Kiteworks Email Protection Gateway administrative service. An administrative service in Kiteworks Email Protection Gateway did not consistently enforce administrator authentication, so the required password check could be bypassed. An attacker who referenced a valid administrator account could potentially create, modify, or delete internal users and managed domains and change their security-feature configuration without authenticating; deleting a managed domain also removes its user accounts and could lock administrators out of the gateway.
- CVE-2026-102105Critical
Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side Request Forgery (SSRF). A remote, unauthenticated attacker can induce the gateway to issue crafted requests to internal or unintended network destinations while the gateway renders message content referencing external resources. This could disclose sensitive internal information or trigger unintended actions on internal systems.
- CVE-2026-102104Critical
Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side Request Forgery (SSRF). A remote, unauthenticated attacker can induce the gateway to issue crafted requests to internal or unintended network destinations while the gateway performs an online certificate status check for an inbound message. This could disclose sensitive internal information or disrupt gateway operation.
- CVE-2026-102103Critical
Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side Request Forgery (SSRF). A remote, unauthenticated attacker can induce the gateway to issue crafted requests to internal or unintended network destinations while the gateway retrieves a certificate revocation list in an inbound message. This could disclose sensitive internal information or disrupt gateway operation.
- CVE-2026-102102Critical
Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side Request Forgery (SSRF). A remote, unauthenticated attacker can induce the gateway to issue crafted requests to internal or unintended network destinations while the gateway retrieves an issuer certificate in an inbound message. This could disclose sensitive internal information or disrupt gateway operation.
- CVE-2026-102095Critical
Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side Request Forgery. The gateway performed server-side fetches of URLs contained in the message content it processed, without adequately restricting the fetch destination. A remote, unauthenticated sender could craft a message that caused the gateway to issue requests to internal services and cloud instance metadata endpoints and return the responses, potentially disclosing sensitive internal data and, depending on the internal service reached, affecting its state.
Original NVD description (English source)
Nextcloud End-to-end encryption app provides all the necessary APIs to implement End-to-End encryption on the client side. By providing an invalid meta data file, an attacker can make previously dropped files inaccessible. It is recommended that the Nextcloud End-to-end encryption app is upgraded to version 1.12.4 that contains the fix.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

