JsdiffApplication · Kpdecker

CVE-2026-24001

HIGH · 7.5 CVSS v3.1 Published 2026-01-22
Fix available
A fix is available. Upgrade to 3.5.1 / 4.0.4 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click Patch available

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 · unedited
jsdiff is a JavaScript text differencing implementation. Prior to versions 8.0.3, 5.2.2, 4.0.4, and 3.5.1, attempting to parse a patch whose filename headers contain the line break characters `\r`, `\u2028`, or `\u2029` can cause the `parsePatch` method to enter an infinite loop. It then consumes memory without limit until the process crashes due to running out of memory. Applications are therefore likely to be vulnerable to a denial-of-service attack if they call `parsePatch` with a user-provided patch as input. A large payload is not needed to trigger the vulnerability, so size limits on user input do not provide any protection. Furthermore, some applications may be vulnerable even when calling `parsePatch` on a patch generated by the application itself if the user is nonetheless able to control the filename headers (e.g. by directly providing the filenames of the files to be diffed). The `applyPatch` method is similarly affected if (and only if) called with a string representation of a patch as an argument, since under the hood it parses that string using `parsePatch`. Other methods of the library are unaffected. Finally, a second and lesser interdependent bug - a ReDOS - also exhibits when those same line break characters are present in a patch's *patch* header (also known as its "leading garbage"). A maliciously-crafted patch header of length *n* can take `parsePatch` O(*n*³) time to parse. Versions 8.0.3, 5.2.2, 4.0.4, and 3.5.1 contain a fix. As a workaround, do not attempt to parse patches that contain any of these characters: `\r`, `\u2028`, or `\u2029`.

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
How this class of weakness works · CWE-400

A single request can consume unbounded CPU, memory, or connections, so a modest amount of malicious traffic exhausts the service. The result is denial of service for everyone else. Remediation is enforcing limits, quotas, and timeouts on what any one request can use.

General guidance for the uncontrolled resource consumption class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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
JsdiffApplication
Affected:< 3.5.1>= 4.0.0, < 4.0.4>= 5.0.0, < 5.2.2>= 6.0.0, < 8.0.3

CVSS 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

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.

dbcve · scoped
Upgrade available Upgrade to 3.5.1 / 4.0.4 / 5.2.2 or later
Fixed in 3.5.14.0.45.2.2
Vendor patch github.com →
Recommended fix High confidence

jsdiff version 8.0.3 (or 5.2.2/4.0.4/3.5.1 depending on your major version branch)

  1. 1. Identify all instances of the jsdiff library in your project dependencies (package.json, package-lock.json, yarn.lock, etc.)
  2. 2. Run `npm list jsdiff` or `yarn list jsdiff` to see current installed versions
  3. 3. Update jsdiff to a fixed version based on your current major version line:
  4. - If using major version 3.x: upgrade to 3.5.1 or later
  5. - If using major version 4.x: upgrade to 4.0.4 or later
  6. - If using major version 5.x: upgrade to 5.2.2 or later
  7. - If using major version 6.x or 7.x: upgrade to 8.0.3 or later
  8. 4. Run `npm update jsdiff` or `yarn upgrade jsdiff` to apply the fix
Caveat No major breaking changes reported in the patch; this is a security fix addressing resource exhaustion. However, if your application relies on patches containing \r, \u2028, or \u2029 in filenames, those will now be properly parsed instead of causing infinite loops.

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

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Peer-ranked notes from engineers who’ve handled CVE-2026-24001 in production — separate from our analysis above.

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