VulnerabilityPublished 18 Mar 2026Updated 19 Mar 2026

CVE-2026-29856: aapanel · CVE-2026-29856 is a high-severity

Affects aapanelSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

7.5High

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: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 18 Mar 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 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
GitHubaapanel/aapanel`pkg:github/aapanel/aapanel`Other threats	Affected =7.57.0	Fixed in–

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

AI-suggested

Restrict network access to the aaPanel management interface and VirtualHost configuration endpoints using firewalls or access control lists to limit exposure to trusted IP addresses.
Implement input validation and sanitization on any user-supplied data that interacts with VirtualHost configurations to prevent malicious regex patterns from being processed.
Monitor system resource usage and logs for unusual spikes in CPU utilization or repeated parsing failures indicative of ReDoS attempts.
Deploy Web Application Firewalls (WAFs) with custom rules to detect and block suspicious input patterns targeting the VirtualHost parser.
Maintain up-to-date backups and incident response plans to quickly recover from potential service disruptions.
Stay informed on aaPanel vendor announcements and apply security patches or updates promptly once available.
Consider isolating the aaPanel service in a container or virtual machine to limit the impact of resource exhaustion on other critical systems.
Conduct regular security assessments and penetration testing focusing on input validation and resource consumption vulnerabilities.

Description

CVE-2026-29856 is a high-severity vulnerability in the VirtualHost configuration parser of aaPanel version 7.57.0 that allows attackers to trigger a Regular Expression Denial of Service (ReDoS) via crafted input. This vulnerability does not affect confidentiality or integrity but can severely impact availability by causing excessive resource consumption. Exploitation requires no privileges or user interaction and can be performed remotely over the network. No known exploits are currently in the wild, and no patches have been published yet. Organizations using aaPanel 7.57.0 should be aware of potential service disruptions and monitor for suspicious input patterns targeting VirtualHost configurations. Mitigation involves restricting access to the affected service, input validation, and applying patches once available.

Impact

The primary impact of CVE-2026-29856 is on the availability of services managed by aaPanel 7.57.0. Successful exploitation can cause the VirtualHost configuration parser to consume excessive CPU resources, potentially leading to server slowdowns or crashes. This can disrupt web hosting services, causing downtime for hosted websites and applications. Organizations relying on aaPanel for web hosting management may experience service interruptions, leading to loss of revenue, customer dissatisfaction, and reputational damage. Since the attack requires no authentication and can be launched remotely, attackers can easily target vulnerable systems at scale. The vulnerability does not compromise data confidentiality or integrity, but the denial of service can indirectly affect operational capabilities and incident response efforts. The absence of known exploits in the wild currently limits immediate widespread impact, but the vulnerability remains a significant risk until patched.

Summary

CVE-2026-29856 is a vulnerability identified in the VirtualHost configuration handling and parsing component of aaPanel version 7.57.0, a popular web hosting control panel. The issue arises from the use of inefficient or vulnerable regular expressions in the parsing logic, which can be exploited by an attacker supplying specially crafted input. This crafted input triggers a Regular Expression Denial of Service (ReDoS) attack, where the vulnerable regex engine consumes excessive CPU resources, leading to service slowdown or complete denial of service. The vulnerability is remotely exploitable without requiring authentication or user interaction, increasing its risk profile. The CVSS v3.1 base score is 7.5, reflecting high severity due to the ease of exploitation and significant impact on availability. The vulnerability is categorized under CWE-400 (Uncontrolled Resource Consumption), highlighting the risk of resource exhaustion. No patches or fixes have been released at the time of publication, and no active exploits have been reported in the wild. The lack of confidentiality or integrity impact means data theft or modification is not a concern here, but service disruption can affect business continuity and user trust.

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).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Mar 2026, 01:15 UTC

WeaknessesCWE-400

Technical details

References

Community reviews

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