CVE-2026-55090Etherpad: Stored XSS in HTML export via unescaped attribute-pool values
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 5.3 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
- Weakness (CWE)
- CWE-79
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Deferred
- Record last updated
- Aug 20, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
ether etherpad ether:etherpad (from the name) | before 3.3.0 | CNA record |
References
- https://github.com/ether/etherpad/security/advisories/GHSA-2jp7-wwpg-3p9wx-refsource-confirm
- https://github.com/ether/etherpad/pull/7905x-refsource-misc
- https://github.com/ether/etherpad/commit/86c56cf827dd6e5ff1b6cd3760f87adc47f58bb1x-refsource-misc
- https://github.com/ether/etherpad/releases/tag/v3.3.0x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.