Toggl OÜ Toggl Track Extension postMessage origin validation

published 2026-08-31 2 mo ago modified 2026-08-31 2 mo ago also EUVD-2026-68679

cvss: 5.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits: 0; none known

A security vulnerability has been detected in Toggl OÜ Toggl Track Extension 4.11.16. This affects an unknown function of the component postMessage Handler. The manipulation leads to origin validation error. It is possible to initiate the attack remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-31)

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/xryj920/chrome_extensions/blob/main/Toggl%20O%C3%9C%20Toggl%20Track%204.11.16%20accepts%20forged%20session-state%20messages%20through%20an%20unauthenticated%20postMessage%20handler referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
CNA	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L/E:P/RL:X/RC:R
CNA	3.0	5.4	CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L/E:P/RL:X/RC:R
CNA	2.0	6.4	AV:N/AC:L/Au:N/C:N/I:P/A:P/E:POC/RL:ND/RC:UR
CNA	4.0	2.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
CNA	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
CNA	2.0	6.4	AV:N/AC:L/Au:N/C:N/I:P/A:P

Affected products

Toggl OÜ Toggl Track Extension

Classification

Weakness

CWE-346 Origin Validation Error
CWE-345 Insufficient Verification of Data Authenticity

References

github.com /xryj920/chrome_extensions/blob/main/Toggl%20O%C3%9C%20Toggl%20Track%204.11.16%20accepts%20forged%20session-st
exploit
vuldb.com /vuln/397230
vdb-entry
vuldb.com /vuln/397230/cti
signature, permissions-required
vuldb.com /cve/CVE-2026-82811
third-party-advisory
vuldb.com /submit/875273
third-party-advisory

Sources

CVE List CVE-2026-82811
NVD CVE-2026-82811

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary