CVE-2026-82257 PUBLISHED

SvelteKit before 2.69.1 Prototype Pollution via File Input

Assigner: VulnCheck
Reserved: 28.08.2026 Published: 28.08.2026 Updated: 28.08.2026

SvelteKit versions before 2.69.1 contain a prototype pollution vulnerability in remote form functions with file input fields that accept arbitrary user-controlled path names. Attackers can manipulate the deletion path to remove methods on the prototype, potentially disabling application functionality.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CVSS Score: 5.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	Low	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
CVSS Score: 4.3

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

CVSS 3.1

Product Status

Vendor	sveltejs
Product	kit
Versions	Default: unaffected affected from 0 to 2.69.1 (excl.) Version 2.69.1 is unaffected

Credits

iaohkut-from-NightWolf-Team reporter
dummdidumm finder

References

Problem Types

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') CWE