CVE-2026-64964
ATutor generates predictable email confirmation tokens due to the use of insufficiently random values in the account confirmation functional
CVSS
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No CVSS
EPSS
0.4%
p30
KEV
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Exploit Today
9
0-100
Published: Aug 20, 2026 · Last modified: Aug 28, 2026 · CWE-340
0.4%EPSS · 30 days0.4%
2026-09-262026-10-25
ATutor generates predictable email confirmation tokens due to the use of insufficiently random values in the account confirmation functionality. Due to the use of predictable values related to user registration, an attacker who knows or can predict these values can guess valid account activation tokens. This allows an attacker to activate an unconfirmed account without access to the victim's email inbox. Product is no longer actively supported and the vulnerabilities have not been fixed. Only version 2.2.4 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.
CVECVSSEPSSKEVRExploitTitleMod.
CVE-2026-799805.6 MED6.7%
——2The DHCPv4 client in subsys/net/lib/dhcpv4/dhcpv4.c maintained its transaction identifier (iface->config.dhcpv4.xid) as a counter rather than as a per-transaction random value. It was seeded once with sys_rand32_get() in dhcpv4_start_internal(), incremented by one in dhcpv4_send_discover() and dhcpv4_send_decline(), and never changed by dhcpv4_send_request() — so every RENEWING and REBINDING exchange reused, unchanged, the identifier that had already appeared on the wire in the broadcast DHCPDISCOVER at boot, and where the identifier did move it moved predictably by one. RFC 2131 4.1 requires a single identifier per transaction, chosen so that clients are unlikely to collide.
This identifier is the client's only unpredictable reply-validation token. net_dhcpv4_input() accepts a BOOTP reply on op, a matching xid, and a matching chaddr (the interface MAC, which is public); the UDP callback is registered with a wildcard remote address and port, and no server-identifier or source-address check is applied. An attacker who learns one identifier — for example any host on the same segment that sees the broadcast DHCPDISCOVER, or a DHCP server or relay on a network the device previously joined — therefore retains a valid token for the device's whole uptime, and can predict the identifiers of later exchanges, without having to observe the unicast renew traffic or race the legitimate server.
A forged reply that passes those checks has effect regardless of client state, because dhcpv4_parse_options() applies its side effects before the state machine gate in dhcpv4_handle_reply(): the router option calls net_if_ipv4_set_gw() and the DNS option calls dns_resolve_reconfigure(). A single accepted datagram can thus repoint the device's default gateway and resolvers at attacker-controlled addresses, redirecting its traffic; during RENEWING or REBINDING a forged DHCPACK re-binds the lease with attacker-chosen parameters and a forged DHCPNAK removes the address and restarts configuration.
The fix draws a fresh sys_rand32_get() value at each point where a transaction begins — entering SELECTING, RENEWING and REBINDING, and at the INIT/INIT-REBOOT entry taken when an interface with a lease goes down — while REQUESTING and DECLINE keep the identifier of the exchange they belong to, as RFC 2131 requires. As a side effect the client also no longer discards a slow server's offer after retransmitting a discover, and the initial-discover backoff now draws its own randomness instead of deriving it from the identifier.2dCVE-2026-463476.8 MED16.7%
——5The Goobi viewer is a web application that allows digitised material to be displayed in a web browser. Prior to version 26.05, when a password reset link is visited, the application generates a replacement password in a predictable way and emails it to the account holder. The insufficient entropy allows the password to be brute-forced by an attacker who can approximate the server-side generation time. Exploiting this finding in isolation requires the victim to have triggered the reset themselves and the attacker to infer the server time from network or email metadata. This issue has been patched in version 26.05.2dCVE-2026-463466.5 MED26.6%
——8The Goobi viewer is a web application that allows digitised material to be displayed in a web browser. Prior to version 26.05, the password reset token is predictably based on the time of the reset request. An attacker who knows the target's email address can request a reset and then brute-force the token. Exploiting this finding alone forces an unauthorized password reset on any account. This issue has been patched in version 26.05.2dCVE-2026-854968.8 HIG16.2%
——5The Botslab G980H dash camera firmware generates session identifiers using a small sequential value space rather than a suitably unpredictable source. An unauthenticated attacker with adjacent network access and knowledge that an active session exists could potentially determine a valid session identifier and use it to bypass intended authorization controls.30dCVE-2026-956537.5 HIG46.9%
——14Concrete CMS Community Store before 2.7.8 derives digital product download tokens from order creation timestamps instead of random values, making tokens predictable. Unauthenticated attackers can enumerate sequential order and file identifiers to calculate valid download tokens and retrieve digital goods purchased by other customers.30dCVE-2025-14602—40.0%
——12The application generates uploaded file names using a weak and predictable method based on the request timestamp. This allows a remote attacker to accurately guess or brute-force the generated filename within a short time window. An attacker can successfully locate and access uploaded files, which can be used to facilitate further attacks.
Apply patch from vendor https://vsdesk.ru/ . Versions 14.0101 and on have the patch.19d