Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-118173— MISP Guard Incomplete Tag Validation Allows Non-Allowed Taxonomy Tags to Bypass Feed Policy Enforcement

Quick assessment

Affected
MISP misp-guard
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

MISP Guard 是一款用于在 MISP 情报源数据上实施安全策略的代理组件，其存在对必需分类法标签（taxonomy tags）的验证检查不完整的问题。当情报源事件或其属性携带属于必需分类法（例如 TLP）的标签时，该代理仅验证是否至少有一个标签与配置允许的标签列表匹配，而未验证该事件或属性上存在的所有属于该必需分类法的标签是否均包含在允许列表中。因此，一个事件或属性可能同时携带允许标签（如 ）和未允许标签（如 或 ），仍能通过 MISP Guard 的策略检查。这导致被标记为更高密级或更高敏感度的数据，能够

CVSS 6.1 · Medium

Affected Version Matrix 1

VendorProduct Version RangeStatus
MISP misp-guard < 1.4 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-118173

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
MISP Guard Incomplete Tag Validation Allows Non-Allowed Taxonomy Tags to Bypass Feed Policy Enforcement
Source: CVE Program / CVE List V5
Vulnerability Description
MISP Guard, a proxy that enforces security policies on MISP feed data, contained an incomplete validation check for required taxonomy tags. When a feed event or its attributes carried tags belonging to a required taxonomy (for example, TLP), the guard only verified that at least one tag of that taxonomy matched the configured allowed list. It did not verify that every tag of the required taxonomy present on the event or attribute was in the allowed list. As a result, an event or attribute could simultaneously carry an allowed tag (e.g., tlp:clear) and a non-allowed tag (e.g., tlp:red or tlp:amber) and still pass the guard's policy check. This allowed data marked with a higher classification or sensitivity level to be distributed through feeds configured to only distribute lower-classification data, effectively bypassing the intended data-handling restrictions. The vulnerability affected both event-level and attribute-level tag validation, including attributes nested within objects and shadow attributes. An attacker with the ability to author or modify MISP events in a feed source could include non-allowed taxonomy tags alongside allowed ones to exfiltrate more sensitive data to feed consumers than the guard policy intended to permit.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
输入验证不恰当
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
MISP misp-guard 0 ~ 1.4 cpe:2.3:a:misp:misp-guard:*:*:*:*:*:*:*:*

II. Public POCs for CVE-2026-118173

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-118173

请登录查看更多情报信息。

Other References for CVE-2026-118173 (1)

IV. Related Vulnerabilities

Same product: misp-guard
Same vendor: MISP
Same weakness: CWE-20