CVE-2026-55086: ether etherpad · Link Following
Affects ether etherpadSource CVE Database V5
Not known to be exploited · CVSS 4.2 Medium : upgrade to 3.1.0 when convenient.
Data as of 26 Oct 2026, 09:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-08-25.
- Patch
- Available – fixed in 3.1.0
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:NExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 19 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by GitHub, Inc.
, 64 days before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 6 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade ether etherpad to 3.1.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| etheretherpad | Affected
| Fixed in
|
Description
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.
References
- github.com/ether/etherpad/security/advisories/GHSA-2jwf-f4xq-f24h (opens in a new tab)
- github.com/ether/etherpad/pull/7784 (opens in a new tab)
- github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996 (opens in a new tab)
- github.com/ether/etherpad/releases/tag/v3.1.0 (opens in a new tab)