React Router is a router for React. In versions 7.0.0 through 7.17.0, the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. This issue is a follow up to CVE-2026-42342, and does not does not impact React Router applications using Declarative Mode () or Data Mode (createBrowserRouter/). This issue has been fixed in version 7.18.0.
CVE-2026-55685
HIGHPre-NVD 8.78.7—Trending — 3 sources updated this week
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 56% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.7Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.7
- EG Score
- 8.7(medium)
- EG Risk
- 54(Track)EG Risk 54/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity87% × 45%Exploitation1% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 44%
- KEV
- Not listed
Published
July 24, 2026
Last Modified
July 28, 2026
Advisory Details (6)
Auto-updated Jul 27, 2026Patch available. Sources: github_commit, github_release, github, github_pr.
github_release Patch Available
v7.18.0
Patch available: remix-run/react-router [email protected]
https://github.com/remix-run/react-router/releases/tag/[email protected]generic
react-router/CHANGELOG.md at main · remix-run/react-router · GitHub
https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180github_commit Patch Available
commit 09e6020d1950 (remix-run/react-router)
Patch available: remix-run/react-router [email protected] (contains commit 09e6020d1950)
https://github.com/remix-run/react-router/commit/09e6020d1950e54f361f7ad00938ecd4dde60929github_pr Patch Available
Optimize route matching internals
Patch available: remix-run/react-router [email protected] (PR #15186 merged 2026-06-15)
https://github.com/remix-run/react-router/pull/15186github Patch Available
DoS via unbounded path expansion in __manifest endpoint · Advisory · remix-run/react-router · GitHub
https://github.com/remix-run/react-router/security/advisories/GHSA-8x6r-g9mw-2r78github Patch Available
Unauthenticated Denial of Service in React Router __manifest endpoint · Advisory · remix-run/react-router · GitHub
https://github.com/remix-run/react-router/security/advisories/GHSA-chx6-hx7r-mcp5Vendor Advisories for CVE-2026-55685(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| react-router | — | 7.18.0 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 13× in last 7d / 13× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-30 18:48 UTCEG score recompute
- 2026-07-30 16:28 UTCEPSS rescore
- 2026-07-30 05:36 UTCEG score recompute
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-28 16:31 UTCEG score recompute
- 2026-07-28 15:37 UTCEPSS rescore
- 2026-07-28 14:37 UTCEG score recompute
- 2026-07-28 13:44 UTCEG score recompute
- 2026-07-27 22:25 UTCEG score recompute
- 2026-07-27 21:50 UTCEG score recompute▲ 8.70
- 2026-07-27 21:49 UTCMITRE cvelistV5CVSS v3 → 8.7 · CVSS v4 → 8.7
- 2026-07-27 17:23 UTCEG score recompute
- 2026-07-24 14:12 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-400
Frequently asked(5)
What is CVE-2026-55685?
CVE-2026-55685 is a high vulnerability published on July 24, 2026. React Router is a router for React. In versions 7.0.0 through 7.17.0, the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. This issue is a follow up to CVE-2026-42342, and does not does not impact React…
When was CVE-2026-55685 disclosed?
CVE-2026-55685 was first published in the National Vulnerability Database on July 24, 2026, with the most recent update on July 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55685 actively exploited?
CVE-2026-55685 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 55.7% of all scored CVEs.
What is the CVSS score of CVE-2026-55685?
CVE-2026-55685 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-55685?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55685, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55685
Is Your Infrastructure Affected by CVE-2026-55685?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.