CVE-2025-35436VulnerabilityPublished 17 Sep 2025Updated 30 Sep 2025

CVE-2025-35436: CISA Thorium · Uncaught Exception

Affects CISA ThoriumSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
CISA Thorium	Affected =1.0.0	Fixed in–

AI-suggested

European organizations should immediately verify if they are running CISA Thorium version 1.0.0 and plan to upgrade to the fixed version containing commit 6a65a27 or later. In the absence of an official patch, temporary mitigations include implementing network-level protections such as firewall rules or web application firewalls (WAFs) to restrict or filter suspicious inputs targeting the account verification email handling endpoints. Monitoring logs for unusual or malformed email address inputs can help detect attempted exploitation. Additionally, organizations should review their Rust codebases for unsafe use of '.unwrap()' or similar error handling anti-patterns and adopt more robust error handling practices, such as using 'match' statements or 'expect()' with clear error messages. Conducting thorough input validation and sanitization on all external inputs is critical. Finally, ensure that incident response plans include procedures for quickly restarting or restoring the Thorium service in case of crashes to minimize downtime.

Description

CISA Thorium uses '.unwrap()' to handle errors related to account verification email messages. An unauthenticated remote attacker could cause a crash by providing a specially crafted email address or response. Fixed in commit 6a65a27.

Impact

For European organizations using CISA Thorium version 1.0.0, this vulnerability poses a risk of service disruption due to crashes triggered by unauthenticated remote attackers. The impact is primarily on availability, potentially causing denial of service conditions that could interrupt critical workflows involving account verification processes. While the vulnerability does not expose sensitive data or allow unauthorized data modification, the downtime or instability could affect operational continuity, user trust, and compliance with service availability requirements under regulations such as the EU's NIS2 Directive. Organizations relying on Thorium for security or infrastructure management may face increased risk of operational disruption, especially if the service is internet-facing or exposed to untrusted networks. The lack of required authentication and ease of exploitation increase the likelihood of opportunistic attacks, although no active exploitation is currently known.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Oct 2025, 00:17 UTC

WeaknessesCWE-248

Technical details

References

Community reviews

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