CVE-2026-12888Network attack vector

Alert spoofing via unescaped webhook fields

Published Jun 22, 2026 · Updated Jun 22, 2026

HTML injection in Canarytokens before sha-8ab4dccd allows remote attackers to place links and images in Google Chat alerts. The GoogleChatTextWithTopLabel.dict method serializes attacker-controlled User-Agent and Referer values into decoratedText without HTML escaping. Exploitation requires a Canarytoken hit and a configured Google Chat webhook; the forged content appears to originate from the alert.

CVSS severity0.0
None
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTML injection in Canarytokens before sha-8ab4dccd allows remote attackers to place links and images in Google Chat alerts. The GoogleChatTextWithTopLabel.dict method serializes attacker-controlled User-Agent and Referer values into decoratedText without HTML escaping. Exploitation requires a Canarytoken hit and a configured Google Chat webhook; the forged content appears to originate from the alert.

The record

CVE
CVE-2026-12888
Published
Jun 22, 2026
Updated
Jun 22, 2026
Vendor
Thinkst Applied Research
Product
Canarytokens
Classifications
CWE-74, T1566.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4aef1db90 <8ab4dccd
  2. Affected versionversion=sha-4aef1db90 <sha-8ab4dccd

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Thinkst Applied Research · Canarytokensversion=4aef1db90 <8ab4dccd; version=sha-4aef1db90 <sha-8ab4dccd

Published CVSS scores

0.0Thinkst Applied ResearchCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1566.002Spearphishing Link

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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