VulnerabilityPublished 21 Feb 2026Updated 24 Feb 2026

CVE-2026-27212: nolimits4web swiper · Prototype Pollution

Affects nolimits4web swiperSource CVE Database V5

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Not known to be exploited · CVSS 9.4 Critical : upgrade to 12.1.2 as a priority.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 4.0 base score

9.4Critical

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

Contested

Critical score, yet low EPSS after six months

EPSS: 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 12.1.2

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

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

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

Attack Vector: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; 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 Vulnerable System (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).
Subsequent system confidentiality: High: There is a total loss of confidentiality, resulting in all resources within the Subsequent System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Subsequent system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the Subsequent System. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the Subsequent System.
Subsequent system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Subsequent System; 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 Subsequent System (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 v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
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), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 29 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

Upgrade nolimits4web swiper to 12.1.2.

Affected software

Product	Affected	Fixed in
nolimits4webswiper	Affected >=6.5.1 <12.1.2	Fixed in 12.1.2

AI-suggested

To mitigate CVE-2026-27212, organizations should immediately upgrade the swiper library to version 12.1.2 or later, where the vulnerability is patched. If upgrading is not immediately feasible, implement strict input validation and sanitization on all data passed to swiper, specifically filtering out any keys or values that could manipulate prototype chains, including those related to Array.prototype. Employ runtime application self-protection (RASP) or Web Application Firewalls (WAFs) with custom rules to detect and block suspicious payloads attempting prototype pollution. Conduct thorough code reviews and static analysis focusing on object property assignments and prototype manipulations in the application codebase. Monitor application logs for unusual behavior indicative of prototype pollution exploitation attempts. Additionally, isolate critical services and apply the principle of least privilege to limit the impact of potential remote code execution.

Description

Swiper is a free and mobile touch slider with hardware accelerated transitions and native behavior. Versions 6.5.1 through 12.1.1 have a Prototype pollution vulnerability. The vulnerability resides in line 94 of shared/utils.mjs, where the indexOf() function is used to check whether user provided input contain forbidden strings. Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input contained a forbidden key, it is still possible to pollute Object.prototype via a crafted input using Array.prototype. The exploit works across Windows and Linux and on Node and Bun runtimes. Any application that processes attacker-controlled input using this package may be affected by the following: Authentication Bypass, Denial of Service and RCE. This issue is fixed in version 12.1.2.

Impact

The impact of CVE-2026-27212 is significant for organizations worldwide that use the swiper library in web or mobile applications, especially those processing untrusted input. Prototype pollution can lead to severe security breaches such as authentication bypass, allowing attackers to gain unauthorized access. Denial of service conditions may arise from corrupted application state or crashes triggered by polluted prototypes. Remote code execution is particularly dangerous as it can enable full system compromise, data theft, or lateral movement within networks. Since swiper is widely used in front-end development for mobile and web interfaces, many organizations, including e-commerce, SaaS providers, and enterprises with customer-facing applications, are at risk. The vulnerability affects both Windows and Linux environments and multiple JavaScript runtimes, broadening the attack surface. The absence of required authentication or user interaction means attackers can exploit this remotely and autonomously, increasing the threat's severity and urgency for remediation.

Summary

The vulnerability CVE-2026-27212 in the nolimits4web swiper library is a prototype pollution issue classified under CWE-1321. It affects swiper versions from 6.5.1 up to but not including 12.1.2. The root cause lies in the shared/utils.mjs file, specifically at line 94, where the indexOf() function is used to check user input for forbidden strings. Although a prior fix attempted to prevent prototype pollution by filtering out forbidden keys, the check is insufficient because it does not account for pollution via Array.prototype. This allows an attacker to inject malicious properties into Object.prototype, which can then be inherited by all objects, leading to widespread application state corruption. The exploit works on both Windows and Linux platforms and affects applications running on Node.js and Bun runtimes. The consequences of successful exploitation include authentication bypass, denial of service, and remote code execution, making it a highly critical threat. The vulnerability does not require authentication or user interaction, increasing its risk profile. The issue was publicly disclosed on February 21, 2026, and fixed in swiper version 12.1.2. No known exploits are currently reported in the wild, but the high CVSS score reflects the potential severity.

CWE-1321Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution) (opens in a new tab)
Variant weakness
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
Implementation
By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
Architecture and Design
By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
Implementation · Input Validation
When handling untrusted objects, validating using a schema can be used.
OWASP Cheat Sheets
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.1.2 (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
Exploiting Incorrectly Configured Access Control Security Levels (opens in a new tab)
Manipulating User-Controlled Variables (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 28 Feb 2026, 12:39 UTC

Public exploits and detectionGitHub proofs of concept

WeaknessesCWE-1321

Technical details

References

Community reviews

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