CVE-2020-26237
What it is
Highlight.js is a syntax highlighter written in JavaScript. Highlight.js versions before 9.18.2 and 10.1.2 are vulnerable to Prototype Pollution. A malicious HTML code block can be crafted that will result in prototype pollution of the base object's prototype during highlighting. If you allow users to insert custom HTML code blocks into your page/app via parsing Markdown code blocks (or similar) and do not filter the language names the user can provide you may be vulnerable. The pollution should just be harmless data but this can cause problems for applications not expecting these properties to exist and can result in strange behavior or application crashes, i.e. a potential DOS vector. If your website or application does not render user provided data it should be unaffected. Versions 9.18.2 and 10.1.2 and newer include fixes for this vulnerability. If you are using version 7 or 8 you are encouraged to upgrade to a newer release.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account, but needs a user to act. High risk of data tampering.
- Exploit odds
- 1.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.3% in the next 30 days (EPSS).
- Severity: 5.8 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.3% · EPSS, next 30 days
- Weakness
- CWE-471
- Record status
- Modified
Affected
- Highlightjs highlight.js < 9.18.2
- Highlightjs highlight.js < 10.1.2
- Debian Linux 9.0
- Oracle MySQL Enterprise Monitor ≤ 8.0.30
Attack profile CVSS 3.1 · 5.8
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2020-26237.md and follow it. Check whether this project is affected by CVE-2020-26237. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0
- https://github.com/highlightjs/highlight.js/pull/2636
- https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx
- https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0
- https://github.com/highlightjs/highlight.js/pull/2636
- https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx
References
- https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0
- https://github.com/highlightjs/highlight.js/pull/2636
- https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx
- https://lists.debian.org/debian-lts-announce/2020/12/msg00041.html
- https://www.npmjs.com/package/highlight.js
- https://www.oracle.com/security-alerts/cpujul2022.html
- https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0
- https://github.com/highlightjs/highlight.js/pull/2636
- https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx
- https://lists.debian.org/debian-lts-announce/2020/12/msg00041.html
- https://www.npmjs.com/package/highlight.js
- https://www.oracle.com/security-alerts/cpujul2022.html