Unescaped error message included on error page in SvelteKit
Noroxi assessment
Priority: Monitor (action score 8/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.48% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. Special conditions such as timing or configuration are required.
- Fixed version: sveltejs kit 2.8.3.
Low priority for now. Upgrade to sveltejs kit 2.8.3 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. The static error.html template for errors contains placeholders that are replaced without escaping the content first. error.html is the page that is rendered when everything else fails. It can contain the following placeholders: %sveltekit.status% — the HTTP status, and %sveltekit.error.message% — the error message. This leads to possible injection if an app explicitly creates an error with a message that contains user controlled content. Only applications where user provided input is used in the `Error` message will be vulnerable, so the vast majority of applications will not be vulnerable This issue has been addressed in version 2.8.3 and all users are advised to upgrade. There are no known workarounds for this vulnerability.
- Published
- Nov 25, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.5% · 40th percentile
- CWE
- CWE-79
Report tools
Action score
8
Monitor
Low priority for now.
- CVSS
- 8 / 40 · 2.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 2.0
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| svelte | sveltekit | cpe:2.3:a:svelte:sveltekit |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- svelte sveltekitbefore 2.8.3
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
sveltejs kit
- < 2.8.3affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| npm | @sveltejs/kit | before 2.8.3 | 2.8.3 |
Same product
svelte: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-29008SvelteKit framework has Insufficient CSRF protection for CORS requests35Monitor
- CVE-2023-29003SvelteKit has Insufficient Cross-Site Request Forgery Protection35Monitor
- CVE-2026-82261SvelteKit before 2.52.2 CPU Exhaustion via Remote Form Deserialization34Monitor
- CVE-2026-82260SvelteKit before 2.52.2 Memory Exhaustion via Remote Form Deserialization34Monitor
- CVE-2026-82259SvelteKit 2.49.0 before 2.53.3 Denial of Service via form34Monitor
- CVE-2026-82256SvelteKit before 2.69.1 Denial of Service via Remote Form27Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| sveltejs kit | 2.8.3 · description | Vendor (CNA) |
| npm:@sveltejs/kit | 2.8.3 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2024-532610 days apartCross-Site Scripting attack (XSS) on dev mode 404 page in SvelteKit8Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- A
- Scope
- X
Weakness class (CWE)
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')CVSS vector
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/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
nvd-secondary
Root cause
User content is inserted into the page as HTML. The browser interprets the content as code rather than data.
The bug in code
The whole CWE-79 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
commentEl.innerHTML = comment.body;Fixed
commentEl.textContent = comment.body;Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
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References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.