🛡️ CVE-2025-40891 — cmc

🟡 CVSS 4.7 — Medium ✅ No Known Exploit CWE-79 NVD
4.7
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

A Stored HTML Injection vulnerability was discovered in the Time Machine Snapshot Diff functionality due to improper validation of network traffic data. An unauthenticated attacker can send specially crafted network packets at two different times to inject HTML tags into asset attributes across two snapshots. Exploitation requires a victim to use the Time Machine Snapshot Diff feature on those specific snapshots and perform specific GUI actions, at which point the injected HTML renders in their browser, enabling phishing and open redirect attacks. Full XSS exploitation is prevented by input validation and Content Security Policy. Attack complexity is high due to multiple required conditions.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality low, integrity low, availability none.

Weakness class

CVE-2025-40891 is classified as CWE-79: Cross-site Scripting (XSS). User-supplied data is written into a page without escaping, so attacker script runs in the browser of anyone who views it.

Affected software

CVE-2025-40891 is recorded against 2 packages.

  • cmc (fixed in 25.5.0)
  • guardian (fixed in 25.5.0)

Timeline and source

Published on 18 December 2025 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

security.nozominetworks.com
cert-portal.siemens.com

Details

Severity MEDIUM
CVSS Score 4.7
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N
CWE CWE-79
Public Exploit ✅ No
Source NVD
Published 2025-12-18
Updated 2026-08-11
Modified 2026-06-17
Fix URL N/A

Affected Packages

Software From version Fixed in
cmc — 25.5.0
guardian — 25.5.0

Similar Threats

Vulnerability Monitoring

Track new vulnerabilities in cmc

CVE-2025-40891 is rated CVSS 4.7 Medium. BotEraser monitors your WordPress installation and notifies you when software you use appears in our vulnerability database.

Set Up Free Alerts →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.