# CVE-2026-27212

## Summary

- **CVE ID:** CVE-2026-27212
- **Severity:** CRITICAL
- **CVSS Score:** 9.4 (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)
- **CWE:** CWE-1321
- **Published:** Feb 21, 2026
- **Last Modified:** Mar 12, 2026

## 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.

## Affected Products

- nolimits4web — swiper (>= 6.5.1, < 12.1.2)

## References

- [CNA](https://github.com/nolimits4web/swiper/security/advisories/GHSA-hmx5-qpq5-p643)
- [CNA](https://github.com/nolimits4web/swiper/commit/d3e663322a13043ca63aaba235d8cf3900e0c8cf)
- [CNA](https://github.com/nolimits4web/swiper/releases/tag/v12.1.2)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.40%
- **EPSS Percentile:** 33.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._