CVE-2026-41242: protobufjs compiles protobuf definitions into JavaScript (JS) functions

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CRITICAL 9.8REMOTEUPGRADE

CVE-2026-41242 is a critical-severity flaw (CVSS 9.8) affecting protobufjs. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

protobufjs compiles protobuf definitions into JavaScript (JS) functions. In versions prior to 8.0.1 and 7.5.5, attackers can inject arbitrary code in the "type" fields of protobuf definitions, which will then execute during object decoding using that definition. Versions 8.0.1 and 7.5.5 patch the issue.

Why this priority

Critical severity
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-94
Published	2026-04-18
Last modified	2026-09-09

Publisher (CNA): GitHub, Inc. · Vendor: protobufjs project

Last updated 2026-09-09 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-18 17:16 UTCPublished CVE record published
2026-09-09 13:19 UTCUpdated Record last modified

protobufjs project protobufjs UPGRADE

Affected: < 7.5.5 · 8.0.0

Fixed in: 7.5.5

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls protobufjs

2. UPGRADE to 7.5.5

npm install protobufjs@">=7.5.5"

Exact fixes by distribution

npm · protobufjs · FIXED · 8.0.1 · vulnerable: >= 8.0.0, < 8.0.1 · source

npm install protobufjs@">=8.0.1" npm ls protobufjs

Fedora 46 · icecat · FIXED · 153.6.0-2.rh1.fc46 · FEDORA-2026-25e05b5320 · source

sudo dnf upgrade --advisory=FEDORA-2026-25e05b5320

Fedora ELN · edk2 · FIXED · 20260812-14.eln159 · FEDORA-2026-8850ef9153 · source

sudo dnf upgrade --advisory=FEDORA-2026-8850ef9153

RHEL 8 · grafana · NOT AFFECTED

RHEL 9 · grafana · NOT AFFECTED

RHEL AI (RHEL AI) 3 · rhelai3/bootc-cuda-rhel9 · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-gaudi-rhel9 · DEFERRED

RHEL AI (RHEL AI) 3 · rhelai3/bootc-rocm-rhel9 · NO FIX YET

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: 4chech/CVE-2026-41242 (0 stars)
GitHub PoC: Giangdurian/CVE-2026-41242 (0 stars)
Write-up: github.com/protobufjs/protobuf.js/security/advisories/GHSA-xq3m-2v4x-88gg

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-41242?

protobufjs: upgrade to 7.5.5. Exact commands for each OS are on this page.

Is CVE-2026-41242 being exploited?

CVE-2026-41242 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-41242 affect?

CVE-2026-41242 affects protobufjs. Severity is critical (CVSS 9.8). protobufjs compiles protobuf definitions into JavaScript (JS) functions. In versions prior to 8.0.1 and 7.5.5, attackers can inject arbitrary code in the "type" fields of protobuf definitions, which will then execute during object decoding

How urgent is CVE-2026-41242?

Priority 61/100. Critical severity; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-48712 HIGH 7.5 UPGRADE protobufjs compiles protobuf definitions into JavaScript (JS) functions
CVE-2026-54269 MEDIUM 5.3 UPGRADE UPGRADE protobufjs compiles protobuf definitions into JavaScript (JS) functions
CVE-2026-54270 MEDIUM 5.3 UPGRADE protobufjs compiles protobuf definitions into JavaScript (JS) functions
CVE-2026-59877 MEDIUM 5.3 UPGRADE protobufjs compiles protobuf definitions into JavaScript (JS) functions
CVE-2026-59876 MEDIUM 4.8 UPGRADE protobufjs compiles protobuf definitions into JavaScript (JS) functions

References

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