01 Record
CVE-2026-103321
MISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image
HighPUBLISHEDCNA: CIRCL
CNA base score8.3 CVSS v4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N
02 Description
MISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image
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.
- EPSS probability
- 0.36% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 29.4% of scored records. A rank, not a probability.
- NVD base score
- 8.3 (CVSS v4.0), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVD analysis status
- Deferred. NVD last modified this record on 2026-09-30.
- 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
- 2026-09-30 12:19Z28 DAYS AGO
- Last updated
- 2026-09-30 12:44Z28 DAYS AGO
- Reserved
- 2026-09-30
- Assigning CNA
- CIRCL
- Record state
- PUBLISHED
- Severity
- High (CVSS 8.3)
- CNA CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N
- Weaknesses
- Data version
- 5.2
- Document digest
- 3f772e7148f078b75ad0ad2c6419687ca6df79e117092849bf27df47e0d4f27b
05 Affected products
VendorProductVersionsPlatforms
06 References
- github.comSecurity patchhttps://github.com/MISP/MISP/commit/92c7ccc43
07 Remediation
The vulnerability is remediated by enforcing strict server-side validation of the preview image field, restricting it to a well-formed base64-encoded PNG data URL, and by replacing the client-side string-concatenation rendering with DOM-based attribute assignment that does not interpret the value as HTML.