CVE-2025-59826VulnerabilityPublished 23 Sep 2025

CVE-2025-59826: FlagForgeCTF flagForge · Missing Authorization

Affects FlagForgeCTF flagForgeSource CVE Database V5

Not known to be exploited · CVSS 7.6 High · fixed in 2.2.0 : patch FlagForgeCTF flagForge soon.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 3.1 base score

7.6High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.2.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: High
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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 23 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 26 Oct 2026.

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
FlagForgeCTF flagForge	Affected =2.1.0	Fixed in–

AI-suggested

European organizations should immediately upgrade Flag Forge installations from version 2.1.0 to version 2.2.0 or later, where the authorization checks have been properly implemented. Until the upgrade is applied, administrators should restrict platform access to trusted users only and monitor challenge creation activities closely. Implement role-based access controls (RBAC) to ensure only authorized admin users can create or modify challenges. Conduct audits of existing challenges to identify and remove any unauthorized or suspicious content. Additionally, organizations should enforce strong authentication mechanisms to reduce the risk of account compromise. Network segmentation and monitoring of Flag Forge traffic can help detect anomalous behavior indicative of exploitation attempts. Training platform administrators on secure configuration and timely patch management is critical. Finally, organizations should consider deploying web application firewalls (WAFs) with custom rules to detect and block unauthorized challenge creation attempts if immediate patching is not feasible.

Description

Flag Forge is a Capture The Flag (CTF) platform. In version 2.1.0, non-admin users can create arbitrary challenges, potentially introducing malicious, incorrect, or misleading content. This issue has been patched in version 2.2.0.

Impact

For European organizations using Flag Forge 2.1.0, particularly educational institutions, cybersecurity training centers, and companies running internal CTF competitions, this vulnerability poses a substantial risk. Unauthorized creation of challenges can lead to the insertion of malicious content that may execute harmful code on participants' systems or mislead users, degrading the quality and trustworthiness of training exercises. This can result in compromised learning outcomes, potential exposure to malware, and reputational damage. Additionally, the integrity of scoring and competition fairness can be compromised, affecting organizational trust in the platform. Since the vulnerability requires only low-level user privileges, insider threats or compromised user accounts can easily exploit it. The low confidentiality impact suggests limited direct data leakage, but the high integrity impact means that the platform's content and results can be manipulated. Availability impact is low but could increase if malicious challenges cause platform instability. Given the collaborative and competitive nature of CTF platforms, this vulnerability could disrupt training programs and reduce confidence in cybersecurity readiness initiatives across European organizations.

CWE-862Missing Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #4OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Exploitation of Thunderbolt Protection Flaws (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/FlagForgeCTF/flagForge/security/advisories/GHSA-q7pg-qchv-3pc5 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Oct 2025, 00:49 UTC

WeaknessesCWE-862

Technical details

References

Community reviews

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