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01 Record

CVE-2026-55087

Etherpad: x-proxy-path header reflected into admin HTML/JS/CSS (cache-poisoning XSS) and concatenated into redirect (open-redirect)

MediumPUBLISHEDCNA: GitHub_M
CNA base score6.1 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

02 Description

Etherpad: x-proxy-path header reflected into admin HTML/JS/CSS (cache-poisoning XSS) and concatenated into redirect (open-redirect)

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.57% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 47.3% of scored records. A rank, not a probability.
NVD base score
6.1 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD analysis status
Deferred. NVD last modified this record on 2026-09-09.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-08-19 19:29Z2 MO AGO
Last updated
2026-08-21 21:48Z2 MO AGO
Reserved
2026-06-16
Assigning CNA
GitHub_M
Record state
PUBLISHED
Severity
Medium (CVSS 6.1)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weaknesses
  • CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base
  • CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')Base
  • CWE-601URL Redirection to Untrusted Site ('Open Redirect')Base
Data version
5.2
Document digest
7f3b97ae039435d4f83197023ab3fa42c050c1e4667f885a22732d790a92effa

05 Affected products

VendorProductVersionsPlatforms
etheretherpad>= 2.1.0, < 3.1.0—

06 References