CVE-2026-25509VulnerabilityPublished 3 Feb 2026

CVE-2026-25509: ci4-cms-erp ci4ms · Observable Response Discrepancy

Affects ci4-cms-erp ci4msSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 0.28.5.0 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: 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.28.5.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
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: 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: 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 2026-10-25.

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

Upgrade ci4ms and ci4-cms-erp/ci4ms to 0.28.5.0.

Affected software

Product	Affected	Fixed in
ci4-cms-erpci4ms	Affected <0.28.5.0	Fixed in 0.28.5.0
GitHubci4-cms-erp/ci4ms`pkg:github/ci4-cms-erp/ci4ms`Other threats	Affected <0.28.5.0	Fixed in 0.28.5.0

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

AI-suggested

European organizations using ci4ms should immediately upgrade to version 0.28.5.0 or later, where the vulnerability is patched. If upgrading is not immediately feasible, implement application-layer mitigations such as uniform response messages and timing controls during password reset requests to eliminate observable discrepancies. Employ rate limiting and CAPTCHA challenges on password reset endpoints to hinder automated enumeration attempts. Monitor logs for abnormal password reset request patterns that may indicate enumeration activity. Additionally, educate users about phishing risks and encourage strong, unique passwords combined with multi-factor authentication (MFA) to reduce the impact of potential account enumeration. Regularly audit and update CMS components and dependencies to ensure timely application of security patches. Finally, consider implementing Web Application Firewalls (WAFs) with rules designed to detect and block enumeration behaviors specific to ci4ms password reset flows.

Description

CVE-2026-25509 is a medium severity vulnerability in the ci4ms CMS based on CodeIgniter 4, allowing unauthenticated attackers to enumerate registered email addresses via observable response discrepancies during the password reset process. This email enumeration flaw can aid attackers in identifying valid user accounts, facilitating targeted phishing or brute-force attacks. The vulnerability affects ci4ms versions prior to 0.28.5.0 and has been patched in that release. Exploitation requires no authentication or user interaction and can be performed remotely over the network. While it does not directly impact system integrity or availability, the confidentiality of user registration data is compromised. European organizations using ci4ms should upgrade promptly to mitigate this risk. Countries with higher adoption of CodeIgniter-based CMS solutions and significant enterprise or government use of ci4ms are more likely to be affected.

Impact

For European organizations, this vulnerability primarily threatens the confidentiality of user data by exposing registered email addresses. Attackers can leverage this information to craft more convincing phishing campaigns or attempt brute-force attacks on known accounts, increasing the risk of account compromise indirectly. Organizations relying on ci4ms for internal or external-facing portals may face reputational damage if user data is leaked or abused. While the vulnerability does not directly affect system integrity or availability, the reconnaissance advantage it provides can be a stepping stone for more severe attacks. Given the widespread use of CMS platforms in Europe across various sectors including government, education, and private enterprises, the potential for targeted attacks increases. Organizations with sensitive user bases or regulatory obligations under GDPR must treat this vulnerability seriously to avoid compliance issues related to unauthorized data disclosure.

Summary

CVE-2026-25509 identifies an email enumeration vulnerability in ci4ms, a CMS skeleton built on the CodeIgniter 4 framework. The vulnerability arises from an observable response discrepancy during the password reset workflow, where the system’s responses differ based on whether an email address is registered. This behavior allows unauthenticated attackers to confirm the existence of user accounts by analyzing subtle differences in server responses, such as timing, error messages, or response content. The vulnerability is classified under CWE-204 (Observable Response Discrepancy) and affects all ci4ms versions prior to 0.28.5.0. Since the attack vector is network-based and requires no privileges or user interaction, it is relatively easy to exploit. The impact is limited to confidentiality as it leaks user registration information but does not allow direct account compromise or system manipulation. The issue has been addressed in ci4ms version 0.28.5.0 by standardizing responses during password reset requests to prevent enumeration. No public exploits have been reported yet, but the vulnerability can facilitate further attacks such as targeted phishing, credential stuffing, or social engineering by revealing valid user emails.

CWE-204Observable Response Discrepancy (opens in a new tab)
Base weakness
The product provides different responses to incoming requests in a way that reveals internal state information to an unauthorized actor outside of the intended control sphere.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
Implementation
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended).
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
ICMP IP Total Length Field Probe (opens in a new tab)
ICMP IP 'ID' Field Error Message Probe (opens in a new tab)
Application Fingerprinting (opens in a new tab)
System Footprinting (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Feb 2026, 12:01 UTC

WeaknessesCWE-204

Technical details

References

Community reviews

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