CVE-2025-35432VulnerabilityPublished 17 Sep 2025Updated 30 Sep 2025

CVE-2025-35432: CISA Thorium · Uncontrolled Resource Consumption

Affects CISA ThoriumSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium · fixed in 1.1.1 : update CISA Thorium when convenient.

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.
Patch: Available – fixed in 1.1.1

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 prioritize upgrading CISA Thorium to version 1.1.1 or later, where the vulnerability is fixed by implementing a default rate limit of 10 minutes between verification email sends per user. Until the upgrade is applied, organizations can implement additional mitigations such as deploying web application firewalls (WAFs) to detect and throttle repeated verification email requests from the same IP addresses or user accounts. Monitoring email sending patterns and setting alerts for unusual spikes in verification email traffic can help identify exploitation attempts early. Organizations should also review and harden their email infrastructure to handle potential surges and prevent blacklisting. Implementing CAPTCHA or other challenge-response mechanisms on the verification request endpoint can reduce automated abuse. Finally, organizations should educate their users about potential phishing or spam risks arising from such attacks and maintain incident response plans to address availability disruptions promptly.

Description

CISA Thorium does not rate limit requests to send account verification email messages. A remote unauthenticated attacker can send unlimited messages to a user who is pending verification. Fixed in 1.1.1 by adding a rate limit set by default to 10 minutes.

Impact

For European organizations using CISA Thorium version 1.0.0, this vulnerability poses a risk primarily to service availability and operational stability. Attackers could exploit this flaw to flood users with verification emails, potentially causing email system overloads, increased operational costs, and degraded user experience. This could lead to temporary denial of service conditions for legitimate users attempting to verify accounts, impacting onboarding processes and customer trust. Additionally, excessive email traffic could trigger spam filters or blacklisting of the organization's email domains, further disrupting communications. Organizations in sectors with high user verification demands, such as financial services, healthcare, or government agencies, may experience amplified operational impacts. While the vulnerability does not directly compromise sensitive data, the availability disruption could indirectly affect business continuity and compliance with service-level agreements. Given the unauthenticated nature of the exploit, attackers do not need credentials or user interaction, increasing the ease of exploitation and potential scale of impact.

CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Oct 2025, 00:16 UTC

WeaknessesCWE-400

Technical details

References

Community reviews

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