VulnerabilityPublished 27 Feb 2026

CVE-2026-3286: itwanger paicoding · Server-Side Request Forgery

Affects itwanger paicodingSource CVE Database V5

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Public exploit available · CVSS 5.3 Medium.

Data as of 30 Oct 2026, 11:52 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 27 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 30 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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
itwangerpaicoding	Affected 1.0.0 – 1.0.3 4 affected builds	Fixed in–
Mavencom.github.itwanger/paicoding`pkg:maven/com.github.itwanger/paicoding`Other threats	Affected 1.0.0 – 1.0.3 4 affected builds	Fixed in–

CPE configurations (1)

cpe:2.3:a:itwanger:paicoding:*:*:*:*:*:*:*:*

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AI-suggested

Given the lack of official patches, organizations should implement immediate compensating controls. First, restrict outbound HTTP requests from servers running paicoding to only trusted destinations using network-level controls such as firewall rules or proxy whitelisting to prevent SSRF exploitation. Implement input validation and sanitization on the 'img' parameter at the application level if source code modification is possible, ensuring only legitimate URLs or data are accepted. Monitor and log outbound requests from the application server to detect suspicious activity indicative of SSRF attempts. Employ web application firewalls (WAFs) with rules designed to detect and block SSRF patterns targeting the vulnerable endpoint. Isolate the paicoding server within a segmented network zone with minimal access to sensitive internal resources. Regularly review and update access controls and monitor for unusual network traffic. Engage with the vendor or community for updates or unofficial patches and plan for an upgrade once a fixed version is released. Finally, conduct security awareness and incident response planning to quickly identify and respond to potential exploitation.

Description

A vulnerability was identified in itwanger paicoding 1.0.0/1.0.1/1.0.2/1.0.3. The impacted element is the function Save of the file paicoding-web/src/main/java/com/github/paicoding/forum/web/common/image/rest/ImageRestController.java of the component Image Save Endpoint. Such manipulation of the argument img leads to server-side request forgery. The attack may be launched remotely. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.

Impact

The SSRF vulnerability in paicoding can have significant impacts on organizations running affected versions. Attackers can exploit this flaw to make unauthorized requests from the vulnerable server to internal network resources, potentially accessing sensitive data or services not intended to be exposed externally. This can lead to information disclosure, unauthorized internal reconnaissance, or pivoting to other internal systems. While the direct impact on integrity and availability is limited, SSRF can be a stepping stone for more complex attacks such as server-side exploitation or data exfiltration. The lack of authentication requirements and remote exploitability increase the risk of widespread exploitation, especially given the public availability of an exploit. Organizations using paicoding in environments with sensitive internal services or critical infrastructure are at higher risk. The absence of vendor response and patches prolongs exposure, increasing the window for attackers to exploit this vulnerability.

Summary

CVE-2026-3286 is a server-side request forgery vulnerability affecting the itwanger paicoding software versions 1.0.0 to 1.0.3. The vulnerability resides in the Save function of the ImageRestController.java file, which handles image saving operations via the 'img' parameter. Improper validation or sanitization of this parameter allows an attacker to craft malicious input that causes the server to perform arbitrary HTTP requests to internal or external resources. SSRF vulnerabilities can be leveraged to access internal systems, bypass firewalls, or interact with sensitive backend services that are otherwise inaccessible externally. The vulnerability is remotely exploitable without requiring authentication or user interaction, increasing its risk profile. The vendor was contacted but has not issued any patches or advisories, and a public exploit exists, raising the likelihood of exploitation. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges or user interaction needed, and limited impact on confidentiality, integrity, and availability, resulting in a medium severity rating of 5.3. No mitigations or patches are currently available, leaving users exposed. The vulnerability affects all listed versions of paicoding, a product whose market penetration and usage should be evaluated to understand risk scope.

References

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