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.
CVE-2026-82257
Score 4.3 from GitHub Security Advisory published 2026-08-28. a secondary CVSS source baseline 4.3; sources differ by 0.0.
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 4.3
- EG Score
- 4.3(high)
- EG Risk
- 19(Track)EG Risk 19/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity43% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 11%
- KEV
- Not listed
Published
August 28, 2026
Last Modified
August 28, 2026
Advisory Details (2)
Auto-updated Aug 28, 2026SvelteKit before 2.69.1 Prototype Pollution via File Input | Advisories | VulnCheck
https://www.vulncheck.com/advisories/sveltekit-before-2.69.1-prototype-pollution-via-file-inputPrototype pollution in file input deletion path in remote-function forms · Advisory · sveltejs/kit · GitHub
https://github.com/sveltejs/kit/security/advisories/GHSA-866w-xmhq-wj7xVendor Advisories for CVE-2026-82257(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 10× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-30 01:22 UTCEPSS rescore
- 2026-08-29 20:51 UTCGHSA enrichment
- 2026-08-28 19:03 UTCGHSA enrichment
- 2026-08-28 16:36 UTCEG score recompute
- 2026-08-28 16:35 UTCGHSA enrichment
- 2026-08-28 15:37 UTCEG score recompute
- 2026-08-28 15:37 UTCGHSA enrichment
- 2026-08-28 12:22 UTCEG score recompute
- 2026-08-28 11:23 UTCEG score recompute
- 2026-08-28 11:19 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-82257?
When was CVE-2026-82257 disclosed?
Is CVE-2026-82257 actively exploited?
What is the CVSS score of CVE-2026-82257?
How do I remediate CVE-2026-82257?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-82257
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