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Public proof of conceptFix available

CVE-2022-31116

A public proof of concept exists; no exploitation attested.

  • Published2022-07-05
  • WeaknessCWE-670

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Affected versions were found to improperly decode certain characters. JSON strings that contain escaped surrogate characters not part of a proper surrogate pair were decoded incorrectly. Besides corrupting strings, this allowed for potential key confusion and value overwriting in dictionaries. All users parsing JSON from untrusted sources are vulnerable. From version 5.4.0, UltraJSON decodes lone surrogates in the same way as the standard library's `json` module does, preserving them in the parsed output. Users are advised to upgrade. There are no known workarounds for this issue.

Timeline

dates in UTC
  1. 2022-07-0518:15CVE publishedNVD

Versions per branch

NVD · OSV
Fedoraproject fedora
BranchAffectedFixed in
35.x= 35no fix published
36.x= 36no fix published
Ultrajson project ultrajson
BranchAffectedFixed in
5.4< 5.4.05.4.0

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As GitHub_M, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • ultrajson
    Affected
    • = < 5.4.0no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2022-08-03

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • pandasUbuntu:26.10all versions · no fixed version listed
  • pandasUbuntu:26.04:LTSall versions · no fixed version listed
  • pandasUbuntu:25.10all versions · no fixed version listed
  • pandasUbuntu:24.04:LTSall versions · no fixed version listed
  • pandasUbuntu:22.04:LTSall versions · no fixed version listedand 1 other package
  • pandasUbuntu:20.04:LTSall versions · no fixed version listed
  • pandasUbuntu:18.04:LTSall versions · no fixed version listedand 1 other package
  • pandasUbuntu:16.04:LTSall versions · no fixed version listedand 1 other package

29 more package ranges on OSV.dev

Vendor advisories

  • CVE-2022-31116 Red Hat Product Security14 products fixed · 1 known affected

    python-ujson: improper decoding of escaped surrogate characters may lead to string corruption, key confusion or value overwriting

    python-ujson.src as a component of Red Hat OpenStack Platform 13 (Queens)

  • RHSA-2022:8864 Red Hat Product Security7 products fixed

    Red Hat Security Advisory: Red Hat OpenStack Platform 16.1.9 (python-ujson) security update

  • RHSA-2022:8850 Red Hat Product Security7 products fixed

    Red Hat Security Advisory: Red Hat OpenStack Platform 16.2.4 (python-ujson) security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2022:8864 · 7 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  2. No fix planned, says the vendor Red Hat Product Security CVE-2022-31116 · 1 productOut of support scope

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • CISA-ADPSSVC decisionpoc2025-04-22
  • CNACVSS 3.17.5known since 2026-10-23
  • NVDCVSS 3.17.5read 2026-10-23
  • NVDCVSS 2.05read 2026-10-23
  • CNAweakness (CWE)CWE-670known since 2026-10-23
  • FIRST EPSSEPSS score2.5 %2026-11-08
  • OSVaffected packages—
  • GitHub AdvisoriesadvisoryHIGH2022-07-05

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2022-07-05
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-wpqr-jcpx-745r

Frequently asked questions

What is CVE-2022-31116?

UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Affected versions were found to improperly decode certain characters. JSON strings that contain escaped surrogate characters not part of a proper surrogate pair were decoded incorrectly. Besides corrupting strings, this allowed for potential key confusion and value overwriting in dictionaries. All users parsing JSON from untrusted sources are vulnerable. From version 5.4.0, UltraJSON decodes lone surrogates in the same way as the standard library's `json` module does, preserving them in the parsed output. Users are advised to upgrade. There are no known workarounds for this issue.

Is CVE-2022-31116 actively exploited?

A proof-of-concept exploit exists for CVE-2022-31116, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2022-31116?

CVE-2022-31116 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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