CVE-2026-8080

MEDIUM

MISP core - Stored XSS in MISP template (old engine) element attribute type

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-8080. PoCs published by George0Papasotiriou.

AI-analyzed exploit summary This repository demonstrates a DKIM signature verification bypass vulnerability (CVE-2026-8080) caused by improper header canonicalization. The flawed verifier includes extra headers not listed in the 'h=' tag during hash computation, allowing attackers to inject headers that alter email behavior while maintaining a valid signature.

Description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in misp allows Stored XSS. This issue affects MISP before 2.5.37. A stored cross-site scripting vulnerability exists in the template element attribute handling logic. The application accepted arbitrary values for the TemplateElementAttribute type and category fields without validating them against the known MISP attribute type and category definitions. An attacker with permission to create or modify template element attributes could store a crafted type value. This affects the old templating (not more accessible in 2.5.37) engine from MISP which will be removed in 2.5.38

Exploits (1)

github WORKING POC
by George0Papasotiriou · pythonpoc
https://github.com/George0Papasotiriou/CVE-2026-8080-DKIM-Signature-Verification-Bypass-Header-Canonicalization-Flaw-

This repository demonstrates a DKIM signature verification bypass vulnerability (CVE-2026-8080) caused by improper header canonicalization. The flawed verifier includes extra headers not listed in the 'h=' tag during hash computation, allowing attackers to inject headers that alter email behavior while maintaining a valid signature.

Classification
Working Poc 98%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: DKIM verifier implementations with flawed header canonicalization (RFC 6376 non-compliance)
No auth needed
Prerequisites: Access to an email system using a vulnerable DKIM verifier · Ability to send emails with crafted headers
mistral-large-3 · analyzed Aug 03, 2026 Full analysis →

Scores

CVSS v3 5.4
EPSS 0.0014
EPSS Percentile 3.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (2)
misp/misp < 2.5.37 (2 CPE variants)
misp-project/misp < 2.5.37
Published May 07, 2026
Tracked Since May 07, 2026