CVE-2026-2556VulnerabilityPublished 16 Feb 2026Updated 23 Feb 2026

CVE-2026-2556: cskefu · Server-Side Request Forgery

Affects cskefuSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 4.0 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 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system 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 Vulnerable System.
Vulnerable system 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 to the Vulnerable System.
Vulnerable system 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 Vulnerable System 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 Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 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 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
cskefu	Affected =8.0.0 =8.0.1	Fixed in–

CPE configurations (1)

cpe:2.3:a:cskefu:cskefu:*:*:*:*:*:*:*:*

AI-suggested

To mitigate CVE-2026-2556, organizations should first restrict outbound HTTP requests from the cskefu server to only trusted and necessary endpoints using network-level controls such as firewall rules or proxy whitelisting. Implement strict input validation and sanitization on the 'url' parameter to ensure it does not contain malicious or internal addresses, including IP ranges reserved for private networks (e.g., 10.0.0.0/8, 192.168.0.0/16). Employ allowlisting of domains or IPs that the application is permitted to access. Monitor and log outbound requests initiated by the application to detect anomalous or unexpected destinations. If possible, deploy web application firewalls (WAFs) with custom rules to detect and block SSRF patterns targeting the vulnerable endpoint. Regularly scan and audit cskefu instances for signs of exploitation attempts. Engage with the vendor or community for updates or unofficial patches. Finally, educate developers and administrators about SSRF risks and secure coding practices to prevent similar issues.

Description

A security vulnerability has been detected in cskefu up to 8.0.1. This issue affects some unknown processing of the file com/cskefu/cc/controller/resource/MediaController.java of the component Endpoint. The manipulation of the argument url leads to server-side request forgery. The attack may be initiated remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Impact

The SSRF vulnerability in cskefu can have several impacts on affected organizations. Attackers can exploit it to perform unauthorized internal network reconnaissance, potentially discovering sensitive internal services not exposed externally. This can lead to further exploitation of internal systems or data exfiltration. Confidentiality may be compromised if internal resources or metadata are accessed via SSRF. Integrity and availability impacts are generally low but could occur if SSRF is chained with other vulnerabilities. Since exploitation requires no authentication or user interaction, any exposed cskefu instance is at risk. Organizations relying on cskefu for customer service or communication may face service disruptions or data breaches if attackers leverage this flaw. The absence of a vendor patch increases the window of exposure, emphasizing the need for immediate mitigation. Overall, the threat is moderate but could escalate if combined with other vulnerabilities or targeted at high-value internal assets.

Summary

CVE-2026-2556 is a Server-Side Request Forgery vulnerability identified in the cskefu software, specifically affecting versions 8.0.0 and 8.0.1. The vulnerability resides in the MediaController.java file within the Endpoint component, where the 'url' parameter is improperly validated or sanitized. This flaw allows an attacker to manipulate the 'url' argument to force the server to send crafted HTTP requests to arbitrary destinations. SSRF vulnerabilities can be leveraged to access internal services, bypass firewalls, or exfiltrate sensitive data by making the server act as a proxy. The vulnerability is remotely exploitable without requiring authentication or user interaction, increasing its risk profile. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges or user interaction needed, and low impact on confidentiality, integrity, and availability. Despite public disclosure, no active exploitation has been reported, and the vendor has not issued a patch or response. The lack of vendor engagement increases the urgency for organizations to implement their own mitigations. This vulnerability highlights the importance of input validation and restricting server-side HTTP requests to trusted endpoints.

References

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