Golang protojson.Unmarshal function infinite loop when unmarshaling certain forms of invalid JSON

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.6 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U · score source

EPSS

• CVE-2024-24786: 1.26% estimated exploitation activity in the next 30 days; percentile 69.67 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

The protojson.Unmarshal function can enter an infinite loop when unmarshaling certain forms of invalid JSON. This condition can occur when unmarshaling into a message which contains a google.protobuf.Any value, or when the UnmarshalOptions.DiscardUnknown option is set.

Published by the source

6 Mar 2024, 00:31 UTC

Last modified by the source

7 Nov 2024, 19:19 UTC

Source last checked

26 Oct 2026, 15:05 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8r3f-844c-mc37

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# Patch Next advisory brief: CVE-2024-24786

Advisory: Golang protojson.Unmarshal function infinite loop when unmarshaling certain forms of invalid JSON
IDs: CVE-2024-24786, GHSA-8r3f-844c-mc37
Record: https://patchnext.com/advisories/cve-2024-24786 (revision 1, source checked 26 Oct 2026, 15:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: google.golang.org/protobuf/encoding/protojson 1.33.0; google.golang.org/protobuf/internal/encoding/json 1.33.0; google.golang.org/protobuf 1.33.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go google.golang.org/protobuf/encoding/protojson: affected < 1.33.0; fixed in 1.33.0
- Go google.golang.org/protobuf/internal/encoding/json: affected < 1.33.0; fixed in 1.33.0
- Go google.golang.org/protobuf: affected < 1.33.0; fixed in 1.33.0

## Suggested inspection (read-only)
- Go google.golang.org/protobuf/encoding/protojson: check the installed version with your package manager.
- Go google.golang.org/protobuf/internal/encoding/json: check the installed version with your package manager.
- Go google.golang.org/protobuf: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on google.golang.org/protobuf/encoding/protojson, google.golang.org/protobuf/internal/encoding/json, google.golang.org/protobuf.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8r3f-844c-mc37 (GitHub-reviewed advisory GHSA-8r3f-844c-mc37 lists affected ranges: Go google.golang.org/protobuf >=0 =0 =0 <1.33.0)

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