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NVD / CVE Program· CNA VulnCheck

CVE-2026-93981: hono/jsx before 4.13.7 Cross-Site Scripting via Unescaped Strings

LowCVSS 2.3 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 9/100)

  • 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: 0.22% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. Special conditions such as timing or configuration are required.
  • Fixed version: honojs hono 4.13.7.

Low priority for now. Upgrade to honojs hono 4.13.7 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

Primary sources: NVD · CVE.org · FIRST EPSS

hono before 4.13.7 fails to HTML-escape plain strings rendered by hono/jsx as a child or fallback of Suspense, as a string child of ErrorBoundary alongside an asynchronous sibling, as the single child of a Context.Provider, or as the root value passed to renderToString() or renderToReadableStream() from hono/jsx/dom/server. These paths stringify their input and treat the result as already-escaped markup, so an attacker who controls such a string during server-side rendering can inject arbitrary HTML and execute script under the application's origin.

Published
Sep 19, 2026
Updated
Sep 21, 2026
EPSS
0.2% · 13th percentile

Report tools

JSON

Action score

9

Monitor

Low priority for now.

CVSS
9 / 40 · 2.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
2.3
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/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.

Follow CVE-2026-93981

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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.

—

Limit the impact of XSS

This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.

Check security headers

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • honojs hono

    • 4.13.7not affected
    • before 4.13.7affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
npmhonobefore 4.13.74.13.7
Red Hat:hummingbird:1grafana12.4before 0:12.4.10-0.10.hum10:12.4.10-0.10.hum1
Red Hat:hummingbird:1grafana13.1before 0:13.1.6-0.5.hum10:13.1.6-0.5.hum1
Red Hat:hummingbird:1grafana13.1before 0:13.1.6-0.6.hum10:13.1.6-0.6.hum1
Red Hat:hummingbird:1grafana13.2before 0:13.2.1-0.7.hum10:13.2.1-0.7.hum1

Same product

honojs: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-54290Hono: CORS Middleware reflects any Origin with credentials when `origin` defaults to the wildcard
    28Monitor
  • CVE-2026-109955Hono 4.12.4 before 4.13.11 Middleware Bypass via serveStatic Double Decoding
    27Monitor
  • CVE-2026-84365Hono: Incomplete fix for CVE-2026-39408: `toSSG()` still writes files outside the output directory
    26Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-84363Sep 1, 2026 · Hono: Query parser reads parameters after the URL fragment, causing cache-key and proxy interpretation differentials
    23Monitor
  • ← EarlierCVE-2026-84364Sep 1, 2026 · Hono: Unbounded dot-notation nesting in `parseBody()` can cause memory exhaustion
    21Monitor
  • Later →CVE-2026-111757Oct 19, 2026 · Hono: `serveStatic` decodes the request path a second time, leading to bypass of middleware on static paths
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
honojs hono4.13.7Vendor (CNA)
npm:hono4.13.7Package registry (OSV)
red hat:grafana12.40:12.4.10-0.10.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:grafana13.10:13.1.6-0.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:grafana13.20:13.2.1-0.7.hum1 · Red Hat:hummingbird:1Package 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Not on record for this CVE: patch commit or PR link · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
P
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:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/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 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
commentEl.innerHTML = comment.body;

Fixed

ts
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.

ATT&CK techniques

—

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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