Back
CVE-2026-59877
protobufjs: Denial of Service via infinite loop in .proto option parsing
Medium5.3EPSS 0.36%
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.6.5 and 8.6.6, protobufjs parsed option names by advancing through schema tokens until reaching an = token without checking for end of input, so a crafted .proto schema that opens an option declaration and ends prematurely can cause parse, Root.load, or Root.loadSync to loop indefinitely. This issue is fixed in versions 7.6.5 and 8.6.6.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| NVDNVD · Analyzed | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.36% · top 69% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Weakness
Affected products
- affected >= 7.5.0, < 7.6.5
- affected >= 8.0.0, < 8.6.6
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npmprotobufjsGHSA-j3f2-48v5-ccww (opens in a new tab)
References (6)
- https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-j3f2-48v5-ccww (opens in a new tab)x_refsource_CONFIRM
- https://github.com/protobufjs/protobuf.js/pull/2352 (opens in a new tab)x_refsource_MISC
- https://github.com/protobufjs/protobuf.js/commit/10fba6d54815ceecca8a06b9a6db490c8f5d2217 (opens in a new tab)x_refsource_MISC
- https://github.com/protobufjs/protobuf.js/commit/fa5c73add738ceb471e74da8cc2f3727c3d0a69f (opens in a new tab)x_refsource_MISC
- https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v7.6.5 (opens in a new tab)x_refsource_MISC
- https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v8.6.6 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-j3f2-48v5-ccww (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-59877)Record last updated .