CVE-2025-67853VulnerabilityPublished 3 Feb 2026

CVE-2025-67853: moodle · Improper Restriction of Excessive Authentication Attempts

Affects moodleSource CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in 5.1.1 : patch moodle soon.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.1.1, 5.0.4, 4.5.8 +2

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

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

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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Feb 2026
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 2026-10-26.

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

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
Packagistmoodle/moodle`pkg:composer/moodle/moodle`Other threats	Affected =4.1.0 =4.4.0 =4.5.0 =5.0.0 =5.1.0	Fixed in–
GitHubmoodle`pkg:github/moodle`Other threats	Affected >=4.1.0 <4.1.22 >=4.4.0 <4.4.12 >=4.5.0 <4.5.8 >=5.0.0 <5.0.4 >=5.1.0 <5.1.1	Fixed in 4.1.22 4.4.12 4.5.8 5.0.4 5.1.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

In the absence of patches, administrators should implement strict rate limiting on the confirmation email service endpoint to prevent excessive authentication attempts. This can be achieved through web application firewalls (WAFs), reverse proxies, or custom application-level controls that limit the number of confirmation email requests per IP address or user within a defined time window. Additionally, enabling multi-factor authentication (MFA) for user accounts can reduce the risk of unauthorized access even if credentials are compromised. Monitoring logs for unusual spikes in confirmation email requests or failed login attempts can help detect exploitation attempts early. User education on strong password policies and awareness of phishing attempts should complement technical controls. Finally, organizations should maintain up-to-date incident response plans to quickly address any account compromises resulting from this vulnerability.

Description

A flaw was found in Moodle. A remote attacker could exploit a lack of proper rate limiting in the confirmation email service. This vulnerability allows attackers to more easily enumerate or guess user credentials, facilitating brute-force attacks against user accounts.

Impact

The vulnerability primarily threatens the confidentiality of user credentials by enabling attackers to enumerate valid users and perform brute-force password guessing attacks remotely without authentication or user interaction. This can lead to unauthorized access to user accounts, potentially exposing sensitive educational data, personal information, and administrative controls within Moodle environments. Organizations relying on Moodle for education, training, or administrative purposes may face increased risks of account compromise, data breaches, and subsequent lateral movement within their networks. Although the vulnerability does not directly impact system integrity or availability, compromised accounts can be leveraged for privilege escalation or to distribute malware. The absence of known exploits in the wild currently limits immediate widespread impact, but the ease of exploitation and high prevalence of Moodle in educational institutions worldwide make this a significant threat. Failure to address this vulnerability could also erode user trust and lead to regulatory compliance issues related to data protection laws.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Feb 2026, 15:52 UTC

Technical details

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