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Fencer Vulns
medium 6.5

CVE-2026-59896 json

hono/jsx does not isolate context per request, leading to cross-request data disclosure

published 2026-07-08 4 mo ago modified 2026-10-25 14 d ago also GHSA-hvrm-45r6-mjfj , EUVD-2026-42326

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits
0
none known

Summary

Hono is a Web application framework that provides support for any JavaScript runtime. From 4.11.8 before 4.12.27, hono/jsx did not isolate context values per request during server-side rendering, allowing createContext, useContext, jsxRenderer, or useRequestContext data from a different in-flight request to be used after an await in an async component. This issue is fixed in version 4.12.27.

Patch / fix

  • npm hono 4.12.27
  • hono hono 4.12.27

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-59896 updated cvss 6.5

hono: Hono: Information disclosure due to improper context isolation in server-side rendering

  • Red Hat Ansible Automation Platform 2 ansible-automation-platform-27/mcp-server-rhel9, ansible-automation-platform-tech-preview/mcp-server-rhel9 Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9 Red Hat OpenShift Dev Spaces devspaces/code-rhel9
    affected: no fix available “Fix deferred”
  • Red Hat Migration Toolkit for Applications 8 mta/mta-solution-server-rhel9 Red Hat Hardened Images grafana12.4, grafana13.1
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Affected packages

ecosystem package affected fixed in
npm hono
>=4.11.8, <4.12.27
4.12.27

Affected products

  • honojs hono

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.