CVE-2025-54796VulnerabilityPublished 1 Aug 2025Updated 4 Aug 2025

CVE-2025-54796: 9001 copyparty · Uncontrolled Resource Consumption

Affects 9001 copypartySource CVE Database V5

Not known to be exploited · CVSS 7.5 High : upgrade to 1.18.9 soon.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.18.9

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 1 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 2026-10-26.

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 9001 copyparty to 1.18.9.

Affected software

Product	Affected	Fixed in
9001 copyparty	Affected <1.18.9	Fixed in 1.18.9

AI-suggested

European organizations should immediately assess their use of copyparty and identify any instances running versions prior to 1.18.9. The primary mitigation is to upgrade copyparty to version 1.18.9 or later, where this vulnerability is fixed. If immediate upgrading is not feasible, organizations should consider disabling the "filter" feature on the "Recent Uploads" page to prevent the processing of arbitrary RegEx filters. Additionally, implementing network-level protections such as web application firewalls (WAFs) with custom rules to detect and block suspicious RegEx patterns can help reduce exposure. Monitoring server performance and logs for unusual spikes in CPU or memory usage related to the "Recent Uploads" page can provide early detection of exploitation attempts. Limiting access to the copyparty interface to trusted internal networks or authenticated users can also reduce the attack surface. Finally, organizations should incorporate this vulnerability into their vulnerability management and incident response processes to ensure timely detection and remediation.

Description

Copyparty is a portable file server. Versions prior to 1.18.9, the filter parameter for the "Recent Uploads" page allows arbitrary RegExes. If this feature is enabled (which is the default), an attacker can craft a filter which deadlocks the server. This is fixed in version 1.18.9.

Impact

For European organizations using copyparty versions prior to 1.18.9, this vulnerability poses a significant risk to service availability. Organizations relying on copyparty for file sharing and collaboration could experience denial of service conditions if an attacker exploits this flaw by submitting crafted RegEx filters. This could disrupt business operations, especially in sectors where timely file access is critical, such as legal, healthcare, education, and media. Since the attack requires no authentication, any external or internal user with access to the "Recent Uploads" page could trigger the deadlock, potentially enabling denial of service from both insider threats and external attackers. The lack of confidentiality or integrity impact reduces the risk of data breaches, but the availability impact alone can cause operational downtime and reputational damage. Additionally, organizations with compliance obligations under regulations like GDPR must consider the operational risks and potential service interruptions caused by such vulnerabilities. The absence of known exploits in the wild suggests that proactive patching can effectively mitigate the threat before widespread exploitation occurs.

CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-1333Inefficient Regular Expression Complexity (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
Architecture and Design
Use regular expressions that do not support backtracking, e.g. by removing nested quantifiers.
System Configuration
Set backtracking limits in the configuration of the regular expression implementation, such as PHP's pcre.backtrack_limit. Also consider limits on execution time for the process.
Implementation
Do not use regular expressions with untrusted input. If regular expressions must be used, avoid using backtracking in the expression.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
Regular Expression Exponential Blowup (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-833Deadlock (opens in a new tab)
Base weakness
The product contains multiple threads or executable segments that are waiting for each other to release a necessary lock, resulting in deadlock.
Attack patterns
Forced Deadlock (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 9 Aug 2025, 00:58 UTC

WeaknessesCWE-400, CWE-1333, CWE-833

Technical details

References

Community reviews

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