CVE-2026-24001 — jsdiff has a Denial of Service vulnerability in parsePatch and applyPatch
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`.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.6% (30-day exploitation probability)+7
- Technical severity (high)+6
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Kpdecker Jsdiff).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Kpdecker | Jsdiff | < 3.5.1≥ 4.0.0 and < 4.0.4≥ 5.0.0 and < 5.2.2≥ 6.0.0 and < 8.0.3 | Vulnerable | NIST National Vulnerability Database |
| Kpdecker | Jsdiff | version >= 6.0.0, < 8.0.3version >= 5.0.0, < 5.2.2version >= 4.0.0, < 4.0.4version < 3.5.1 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 2.7 | CVSS 4.0 | Low | — | — | security-advisories@github.com via NIST National Vulnerability Database |
| 2.7 | CVSS 4.0 | Low | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.63%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · kpdecker/jsdiff
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 7.5
- Source status changed · → Modified
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
7 on the record
- github.com/kpdecker/jsdiff/security/advisories/GHSA-73rr-hh4g-fpgx
- github.com/kpdecker/jsdiff/pull/649
- github.com/kpdecker/jsdiff/commit/15a1585230748c8ae6f8274c202e0c87309142f5
- github.com/kpdecker/jsdiff/issues/653
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-24001.json
- bugzilla.redhat.com/show_bug.cgi
- access.redhat.com/security/cve/CVE-2026-24001
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-24001 is "jsdiff has a Denial of Service vulnerability in parsePatch and applyPatch", rated High. It affects Jsdiff (Kpdecker); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. EPSS 0.63% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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