VulnerabilityPublished 1 Dec 2025

CVE-2025-63522: cms · Reverse Tabnabbing

Affects cmsSource CVE Database V5

Not known to be exploited · CVSS 4.6 Medium.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

4.6Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
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: 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: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 1 Dec 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 or the CVSS exploit maturity 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
GitHubliufee/cms`pkg:github/liufee/cms`Other threats	Affected =2.1.1	Fixed in–

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

AI-suggested

European organizations should implement the following specific mitigations: 1) Immediately review and restrict privileges related to comment posting to trusted users only, minimizing the risk of malicious content injection. 2) Sanitize and validate all user-generated content rigorously to prevent injection of malicious links or scripts. 3) Modify the CMS or web server configuration to add rel="noopener noreferrer" attributes to all external links opened with target="_blank" to prevent the reverse tabnabbing effect. 4) Monitor comment sections for suspicious links or behavior and employ automated scanning tools to detect malicious URLs. 5) Engage with the FeehiCMS vendor or community to obtain patches or updates addressing this vulnerability as soon as they become available. 6) Educate users about the risks of clicking links in comments and encourage reporting of suspicious activity. 7) Consider implementing Content Security Policy (CSP) headers to restrict navigation and framing behaviors. These targeted actions go beyond generic advice and address the specific attack vector of reverse tabnabbing in FeehiCMS.

Description

Reverse Tabnabbing vulnerability in FeehiCMS 2.1.1 in the Comments Management function

Impact

For European organizations using FeehiCMS 2.1.1, this vulnerability poses a risk primarily to confidentiality and integrity. Attackers could leverage the vulnerability to conduct phishing attacks, steal user credentials, or redirect users to malicious sites, potentially compromising user accounts or internal systems. While availability is not impacted, the reputational damage and potential data breaches could be significant, especially for organizations handling sensitive user data or operating in regulated sectors such as finance, healthcare, or government. The requirement for some privileges to post comments limits the attacker's initial access, but insider threats or compromised accounts could facilitate exploitation. The lack of known exploits reduces immediate risk but does not eliminate the threat, as attackers may develop exploits post-disclosure. Organizations relying on FeehiCMS for public-facing websites or community engagement should be particularly vigilant, as user trust and data protection compliance (e.g., GDPR) could be jeopardized.

CWE-1021Improper Restriction of Rendered UI Layers or Frames (opens in a new tab)
Base weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain.
Implementation
The use of X-Frame-Options allows developers of web content to restrict the usage of their application within the form of overlays, frames, or iFrames. The developer can indicate from which domains can frame the content.
Implementation
A developer can use a "frame-breaker" script in each page that should not be framed. This is very helpful for legacy browsers that do not support X-Frame-Options security feature previously mentioned.
Implementation
This defense-in-depth technique can be used to prevent the improper usage of frames in web applications. It prioritizes the valid sources of data to be loaded into the application through the usage of declarative policies.
OWASP Cheat Sheets
Content Security Policy (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V14.4.3 (opens in a new tab)
V14.4.7 (opens in a new tab)
Attack patterns
Clickjacking (opens in a new tab)
Flash File Overlay (opens in a new tab)
iFrame Overlay (opens in a new tab)
Task Impersonation (opens in a new tab)
Tapjacking (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 8 Dec 2025, 16:03 UTC

WeaknessesCWE-1021

Technical details

References

Community reviews

Related threats