Security readout for executives and security teams
Plain-English summary
Copyparty versions before 1.20.9 have a reflected cross-site scripting issue in the setck URL parameter. An attacker would need a user to open a crafted link. Successful abuse could expose or alter limited browser-session data within the affected site context.
Executive priority
Handle as a routine but timely web application fix. The issue is not known to be actively exploited, but exposed file-sharing services can be attractive phishing targets. Prioritize internet-facing copyparty systems and shared environments.
Technical view
CVE-2026-27948 is CWE-79 reflected XSS in 9001 copyparty before 1.20.9. CVSS 3.1 is 5.4: network attack vector, low complexity, no privileges, user interaction required, with low confidentiality and integrity impact and no availability impact. The vendor advisory and commit identify 1.20.9 as the fix.
Likely exposure
Exposure is limited to organizations running copyparty versions earlier than 1.20.9, especially instances reachable by users through a browser. Public internet exposure increases phishing and link-delivery risk, but exploitation still requires user interaction.
Exploitation context
The provided sources do not report active exploitation, and the CVE is not listed as KEV in the bundle. Abuse depends on convincing a user to visit a malicious URL targeting the vulnerable copyparty instance.
Researcher notes
Available evidence names only copyparty before 1.20.9 and the setck URL parameter. The public bundle provides a vendor advisory and fixing commit, but no exploit-in-the-wild evidence. Avoid broad assumptions about downstream packages or hosted deployments without local verification.
Mitigation direction
- Upgrade copyparty to version 1.20.9 or later.
- Review the GitHub security advisory for vendor-specific guidance.
- Prioritize externally reachable or broadly used copyparty instances.
- Use standard browser and application-layer defenses where already available.
Validation and detection
- Inventory copyparty deployments and record running versions.
- Confirm all instances are on version 1.20.9 or later.
- Review access logs for unusual requests containing the setck parameter.
- Verify remediation against the vendor advisory and fixing commit.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-27948 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N2.82.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/9001/copyparty/security/advisories/GHSA-62cr-6wp5-q43hCVE reference · x_refsource_CONFIRM
- https://github.com/9001/copyparty/commit/31b2801fd041f803f4a3d5c12c7d7cb5419048bcCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.