CVE-2021-28092
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe is-svg package 2.1.0 through 4.2.1 for Node.js uses a regular expression that is vulnerable to Regular Expression Denial of Service (ReDoS). If an attacker provides a malicious string, is-svg will get stuck processing the input for a very long time.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe is-svg npm package versions 2.1.0 through 4.2.1 contain a regular expression vulnerable to Regular Expression Denial of Service (ReDoS). When processing a maliciously crafted SVG string, the regex engine can enter a pathological backtracking scenario causing the process to hang indefinitely.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 2.1.0, <= 4.2.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check if is-svg is installedRun `npm list is-svg` or inspect your package.json dependenciesAffected if is-svg appears in your node_modules or package.json dependencies
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Determine installed versionRun `npm list is-svg` to see the installed version number, or check the version field in node_modules/is-svg/package.jsonAffected if The version is 2.1.0, 2.1.1, 2.2.0, 2.2.1, 2.2.2, 2.2.3, 2.2.4, 2.2.5, 2.2.6, 2.2.7, 2.2.8, 2.2.9, 2.2.10, 2.2.11, 2.2.12, 3.0.0, 3.0.1, 3.1.0, 3.2.0, 4.0.0, 4.1.0, 4.1.1, 4.2.0, or 4.2.1 (any version from 2.1.0 through 4.2.1 inclusive)
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Identify code paths that call is-svgSearch your codebase for calls to is-svg such as `require('is-svg')` or `import isSvg from 'is-svg'`, and identify where the returned function is invoked with user-controlled inputAffected if Your code calls the is-svg function with potentially untrusted SVG strings
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Assess SVG input sourceReview whether the SVG input passed to is-svg originates from untrusted sources such as user uploads, external APIs, or database recordsAffected if The is-svg function processes SVG data from untrusted or user-controlled sources
You are affected if is-svg version 2.1.0 through 4.2.1 is installed AND your application passes SVG strings from untrusted sources to the is-svg function.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade is-svg to version 4.2.2 or later which contains the patched regular expression. Run `npm update is-svg` or `npm install is-svg@latest` and re-run your test suite to confirm SVG validation functionality remains intact.
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-28092 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-28092 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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