GHSA-73rr-hh4g-fpgx
jsdiff has a Denial of Service vulnerability in parsePatch and applyPatch
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
diffnpmDescription
Impact
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 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(n³) time to parse.
Patches
All vulnerabilities described are fixed in v8.0.3.
Workarounds
If using a version of jsdiff earlier than v8.0.3, do not attempt to parse patches that contain any of these characters: \r, \u2028, or \u2029.
References
PR that fixed the bug: https://github.com/kpdecker/jsdiff/pull/649
CVE Notes
Note that although the advisory describes two bugs, they each enable exactly the same attack vector (that an attacker who controls input to parsePatch can cause a DOS). Fixing one bug without fixing the other therefore does not fix the vulnerability and does not provide any security benefit. Therefore we assume that the bugs cannot possibly constitute Independently Fixable Vulnerabilities in the sense of CVE CNA rule 4.2.11, but rather that this advisory is properly construed under the rules as describing a single Vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | diff | ≥ 6.0.0&&< 8.0.3 | 8.0.3 |
| 📦npm | diff | ≥ 5.0.0&&< 5.2.2 | 5.2.2 |
| 📦npm | diff | ≥ 4.0.0&&< 4.0.4 | 4.0.4 |
| 📦npm | diff | all versions | 3.5.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for diff. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update diff to 8.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-73rr-hh4g-fpgx is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-73rr-hh4g-fpgx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-73rr-hh4g-fpgx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-73rr-hh4g-fpgx in your dependencies?
O3 detects GHSA-73rr-hh4g-fpgx across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.