CVE-2025-8555VulnerabilityPublished 5 Aug 2025

CVE-2025-8555: atjiu pybbs · Cross Site Scripting

Affects atjiu pybbsSource CVE Database V5

Not known to be exploited · CVSS 5.1 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

5.1Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 25% 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:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: Passive
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
Vulnerable system availability: None
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: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: None: There is no loss of confidentiality within 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: None: There is no impact to availability within 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 5 Aug 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 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

Affected software

Product	Affected	Fixed in
atjiu pybbs	Affected =6.0	Fixed in–

AI-suggested

To mitigate CVE-2025-8555, organizations should promptly apply the official patch identified by commit 2fe4a51afbce0068c291bc1818bbc8f7f3b01a22 to upgrade pybbs beyond version 6.0.0. In addition to patching, implement strict input validation and output encoding on all user-supplied inputs, particularly the 'keyword' parameter in the /search functionality, to prevent injection of malicious scripts. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. Regularly audit and monitor web application logs for unusual or suspicious requests targeting the search endpoint. Educate users about phishing risks and encourage cautious behavior when clicking on links, especially those received from untrusted sources. If immediate patching is not feasible, consider temporarily disabling or restricting access to the vulnerable search functionality to reduce exposure. Finally, integrate automated vulnerability scanning and penetration testing into the development lifecycle to detect similar issues proactively.

Description

A vulnerability, which was classified as problematic, was found in atjiu pybbs up to 6.0.0. Affected is an unknown function of the file /search. The manipulation of the argument keyword leads to cross site scripting. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The name of the patch is 2fe4a51afbce0068c291bc1818bbc8f7f3b01a22. It is recommended to apply a patch to fix this issue.

Impact

For European organizations using atjiu pybbs version 6.0.0 or earlier, this vulnerability poses a risk primarily to the confidentiality and integrity of user sessions and data. Successful exploitation could allow attackers to execute arbitrary scripts in users' browsers, potentially leading to theft of session cookies, credentials, or other sensitive information. This could facilitate further attacks such as account takeover or unauthorized actions within the forum or community platform. Organizations relying on pybbs for internal or external communication may face reputational damage, data leakage, or compliance issues under GDPR if personal data is compromised. The medium severity rating reflects that while the vulnerability does not directly impact system availability or critical infrastructure, the indirect consequences of compromised user trust and data privacy can be significant. Given the remote exploitability and public disclosure, European entities should prioritize patching to prevent exploitation, especially those with large user bases or sensitive discussions hosted on pybbs platforms.

Summary

CVE-2025-8555 is a cross-site scripting (XSS) vulnerability identified in the atjiu pybbs software, specifically affecting versions up to 6.0.0. The vulnerability resides in an unspecified function within the /search endpoint, where the 'keyword' argument is improperly sanitized or validated. This flaw allows an attacker to inject malicious scripts that execute in the context of a victim's browser when they access the manipulated search functionality. The vulnerability is remotely exploitable without requiring authentication, but it does require some user interaction, such as clicking a crafted link or visiting a maliciously crafted search URL. The CVSS 4.0 base score is 5.1, indicating a medium severity level. The vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L - low privileges, but the description suggests no authentication needed, possibly a minor discrepancy), user interaction required (UI:P), and no impact on confidentiality or availability but low impact on integrity (VI:L). The vulnerability has been publicly disclosed, and a patch identified by commit 2fe4a51afbce0068c291bc1818bbc8f7f3b01a22 is available to remediate the issue. No known exploits are currently observed in the wild, but the public disclosure increases the risk of exploitation attempts. XSS vulnerabilities like this can be leveraged for session hijacking, phishing, or delivering malware payloads, especially in web applications with user-generated content or sensitive user sessions.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Aug 2025, 10:02 UTC

Technical details

References

Community reviews

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