Etherpad is a real-time collaborative editor. Prior to 3.1.0, src/node/handler/ImportHandler.ts and src/node/handler/ExportHandler.ts derive temporary filenames from Math.random() and place them in os.tmpdir(). On a host with a shared world-writable temporary directory, a local unprivileged attacker who predicts a filename can precreate a symbolic link to a file writable by the Etherpad process. Subsequent import or export operations can follow the link through fs.writeFile, fs.rename, or document-conversion output and overwrite the target with partially attacker-controlled content. This issue is fixed in version 3.1.0.
CVE-2026-55086
MEDIUMPre-NVD 4.24.2
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 4.2 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
4.2EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.2Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 4.2
- EG Score
- 4.2(low)
- EG Risk
- 23(Track)EG Risk 23/100SSVC: 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 computedSeverity42% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 4%
- KEV
- Not listed
Published
August 13, 2026
Last Modified
August 19, 2026
Advisory Details (4)
Auto-updated Aug 19, 2026🔬 Proof of concept available. Patch available. Sources: github_pr, github_commit, github_release, github.
github_release Patch Available
v3.1.0
Patch available: ether/etherpad v3.1.0
https://github.com/ether/etherpad/releases/tag/v3.1.0github_commit Patch Available
commit 8c6104c5d5da (ether/etherpad)
Patch available: ether/etherpad v3.1.0 (contains commit 8c6104c5d5da)
https://github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996github_pr Patch Available
harden: assorted server-side tightening for 3.0.2
Patch available: ether/etherpad v3.1.0 (PR #7784 merged 2026-05-17)
https://github.com/ether/etherpad/pull/7784github Patch Available🟡 PoC Available
Import/export use Math.random() for temp file paths; predictable paths on shared /tmp enable symlink-based file overwrite · Advisory · ether/etherpad · GitHub
https://github.com/ether/etherpad/security/advisories/GHSA-2jwf-f4xq-f24hVendor Advisories for CVE-2026-55086(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 2× in last 7d / 3× 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
- 2026-08-19 20:23 UTCEG score recompute
- 2026-08-13 14:52 UTCEG score recompute
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-55086?
CVE-2026-55086 is a medium vulnerability published on August 13, 2026. Etherpad is a real-time collaborative editor. Prior to 3.1.0, src/node/handler/ImportHandler.ts and src/node/handler/ExportHandler.ts derive temporary filenames from Math.random() and place them in os.tmpdir(). On a host with a shared world-writable temporary directory, a local unprivileged…
When was CVE-2026-55086 disclosed?
CVE-2026-55086 was first published in the National Vulnerability Database on August 13, 2026, with the most recent update on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55086 actively exploited?
CVE-2026-55086 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 96.2% of all scored CVEs.
What is the CVSS score of CVE-2026-55086?
CVE-2026-55086 has a CVSS v3 base score of 4.2 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55086?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55086, 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-2026-55086
Is Your Infrastructure Affected by CVE-2026-55086?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.