Vulnerability Report

CVE-2026-27212

Title: Prototype pollution in Swiper

DoS

Proof Of Concept

PoC Available for CVE-2026-27212

CWE Category CWE-1321
Published Date Feb 21, 2026
Modified Date Feb 24, 2026
Exploit Status Available
Score 9.4 CVSS v4.0
Exploit Probability (EPSS)
0.35%

Vulnerability Summary

CVE-2026-27212: 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.

Impacted Vendors

S
swiperjs 1

Reference Links

https://github.com/nolimits4web/swiper/commit/d3e663322a13043ca63aaba235d8cf3900e0c8cf https://github.com/nolimits4web/swiper/releases/tag/v12.1.2 https://github.com/nolimits4web/swiper/security/advisories/GHSA-hmx5-qpq5-p643
CVSS v4.0
Source Entity [email protected]
Severity CRITICAL
9.4
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
N/A
RAW VECTOR 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1
Source Entity [email protected]
Severity HIGH
7.8
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-27212 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/stealths-labs/resize-image-before-upload-secure
View Code
MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector LOCAL
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected Stack

No specific products linked.