OneUptime is a solution for monitoring and managing online services. In version 10.0.11 and prior, the WebAuthn authentication implementation does not store the challenge on the server side. Instead, the challenge is returned to the client and accepted back from the client request body during verification. This violates the WebAuthn specification (W3C Web Authentication Level 2, §13.4.3) and allows an attacker who has obtained a valid WebAuthn assertion (e.g., via XSS, MitM, or log exposure) to replay it indefinitely, completely bypassing the second-factor authentication. No known patches are available.
CVE-2026-28787
CRITICALNVD 9.09.0
EchelonGraph scoreLOW confidence
This critical-severity CVE scores 9.0 under NVD CVSS v3. EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory enrichment pending alignment with NVD CVSS.
Triggered by: NVD CVSS baseline
Sources: ghsa, nvd
9.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.0Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.0
- EG Score
- 9.0(low)
- EG Risk
- 45(Track)EG Risk 45/100SSVC: 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 computedSeverity90% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 20%
- KEV
- Not listed
Published
March 6, 2026
Last Modified
June 17, 2026
References (1)
- security-advisories@githubhttps://github.com/OneUptime/oneuptime/security/advisories/GHSA-gjjc-pcwp-c74m
Patch Availability(1)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| npm | @oneuptime/common | — | ghsa |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 2× in last 7d / 2× 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.
- 2026-07-27 13:50 UTCEG score recompute
- 2026-07-27 13:49 UTCGHSA enrichment
Related CVEs(same CWE)
Same CWE
10 shownCWE-287
Frequently asked(5)
What is CVE-2026-28787?
CVE-2026-28787 is a critical vulnerability published on March 6, 2026. OneUptime is a solution for monitoring and managing online services. In version 10.0.11 and prior, the WebAuthn authentication implementation does not store the challenge on the server side. Instead, the challenge is returned to the client and accepted back from the client request body during…
When was CVE-2026-28787 disclosed?
CVE-2026-28787 was first published in the National Vulnerability Database on March 6, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-28787 actively exploited?
CVE-2026-28787 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 80.2% of all scored CVEs.
What is the CVSS score of CVE-2026-28787?
CVE-2026-28787 has a CVSS v3 base score of 9.0 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-28787?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-28787, 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
Explore the affected products and dependency analysis for CVE-2026-28787
Is Your Infrastructure Affected by CVE-2026-28787?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.