Etherpad is a real-time collaborative editor. Prior to 3.3.0, getHTMLFromAtext in src/node/utils/ExportHtml.ts interpolates values from the exportHtmlAdditionalTagsWithData plugin hook into span data attributes without HTML attribute escaping. A pad editor can place an attacker-controlled value into the attribute pool through moveOpsToNewPool and AttributePool.putAttrib. When a bundled plugin such as ep_font_color or ep_font_size registers the hook, opening the resulting HTML export causes the value to execute as stored cross-site scripting in the Etherpad origin. This issue is fixed in version 3.3.0.
CVE-2026-55090
MEDIUMPre-NVD 5.35.3Trending — 3 sources updated this week
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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: secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.3Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.3
- EG Score
- 5.3(low)
- EG Risk
- 39(Track)EG Risk 39/100SSVC: 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 computedSeverity53% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 43%
- KEV
- Not listed
Published
August 17, 2026
Last Modified
August 20, 2026
Advisory Details (4)
Auto-updated Aug 19, 2026Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available
v3.3.0
Patch available: ether/etherpad v3.3.0
https://github.com/ether/etherpad/releases/tag/v3.3.0github_commit Patch Available
commit 86c56cf827dd (ether/etherpad)
Patch available: ether/etherpad v3.3.0 (contains commit 86c56cf827dd)
https://github.com/ether/etherpad/commit/86c56cf827dd6e5ff1b6cd3760f87adc47f58bb1github_pr Patch Available
Escape exported data attributes and warn on default/placeholder credentials
Patch available: ether/etherpad v3.3.0 (PR #7905 merged 2026-06-07)
https://github.com/ether/etherpad/pull/7905github Patch Available
Stored XSS in HTML export via unescaped attribute-pool values · Advisory · ether/etherpad · GitHub
https://github.com/ether/etherpad/security/advisories/GHSA-2jp7-wwpg-3p9wVendor Advisories for CVE-2026-55090(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 |
|---|---|---|---|
| ep_etherpad-lite | — | 3.3.0 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 7× 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.
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 13:57 UTCEG score recompute
- 2026-08-20 12:42 UTCEG score recompute
- 2026-08-19 20:23 UTCEG score recompute
- 2026-08-19 19:43 UTCEG score recompute▲ 5.30
- 2026-08-19 19:42 UTCMITRE cvelistV5CVSS v3 → 5.3 · CVSS v4 → 5.3 · severity → MEDIUM
- 2026-08-17 17:54 UTCEG score recompute
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-55090?
CVE-2026-55090 is a medium vulnerability published on August 17, 2026. Etherpad is a real-time collaborative editor. Prior to 3.3.0, getHTMLFromAtext in src/node/utils/ExportHtml.ts interpolates values from the exportHtmlAdditionalTagsWithData plugin hook into span data attributes without HTML attribute escaping. A pad editor can place an attacker-controlled value…
When was CVE-2026-55090 disclosed?
CVE-2026-55090 was first published in the National Vulnerability Database on August 17, 2026, with the most recent update on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55090 actively exploited?
CVE-2026-55090 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 56.8% of all scored CVEs.
What is the CVSS score of CVE-2026-55090?
CVE-2026-55090 has a CVSS v3 base score of 5.3 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55090?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55090, 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-2026-55090
Is Your Infrastructure Affected by CVE-2026-55090?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.