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Fencer Intel
high 7.5

CVE-2026-23737 json

seroval Affected by Remote Code Execution via JSON Deserialization

published 9mo ago modified 4mo ago also GHSA-3rxj-6cgf-8cfw , EUVD-2026-3679

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

Summary

seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 1.4.0 and below, improper input handling in the JSON deserialization component can lead to arbitrary JavaScript code execution. Exploitation is possible via overriding constant value and error deserialization, allowing indirect access to unsafe JS evaluation. At minimum, attackers need the ability to perform 4 separate requests on the same function, and partial knowledge of how the serialized data is used during later runtime processing. This vulnerability affects the fromJSON and fromCrossJSON functions in a client-to-server transmission scenario. This issue has been fixed in version 1.4.0.

Patch / fix

  • npm seroval 1.4.1
  • lxsmnsyc seroval 1.4.1
  • opencode openSUSE Tumbleweed 1.18.26-1.1

opensuse advisories openSUSE-SU-2026:11673-1

Is CVE-2026-23737 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2026-23737 updated cvss 7.5

seroval: seroval: Arbitrary Code Execution via Improper JSON Deserialization

  • Red Hat All currently supported Red Hat products
    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
total
Assessed
9mo ago

Exploit prediction

0.58% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
npm seroval
<1.4.1
1.4.1

Affected products

  • lxsmnsyc seroval

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data

References

Sources

Fencer Intel 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.