Cyber Resilience

CVE-2026-26273

CriticalPublic PoC

Published: 13 February 2026

Published
13 February 2026
Modified
18 February 2026
KEV Added
Patch
CVSS Score v3 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0071 48.9th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-26273 is a critical-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Withknown Known. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 48.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Known is a social publishing platform. Prior to 1.6.3, a Critical Broken Authentication vulnerability exists in Known 1.6.2 and earlier. The application leaks the password reset token within a hidden HTML input field on the password reset page. This allows…

more

any unauthenticated attacker to retrieve the reset token for any user by simply querying the user's email, leading to full Account Takeover (ATO) without requiring access to the victim's email inbox. This vulnerability is fixed in 1.6.3.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Direct unauthenticated exploitation of public web app password reset flaw for account takeover matches T1190.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-28508Same product: Withknown Known
CVE-2026-28507Same product: Withknown Known
CVE-2026-29199Shared CWE-640
CVE-2026-34297Shared CWE-200
CVE-2025-22918Shared CWE-200
CVE-2022-50910Shared CWE-640
CVE-2026-2262Shared CWE-200
CVE-2026-22237Shared CWE-200
CVE-2026-23659Shared CWE-200
CVE-2026-32865Shared CWE-200, CWE-640

Affected Assets

withknown
known
≤ 1.6.3

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-200

Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.

addresses: CWE-200

Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.

addresses: CWE-200

Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.

addresses: CWE-200

By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.

addresses: CWE-200

Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.

addresses: CWE-200

Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.

addresses: CWE-200

Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.

addresses: CWE-200

Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.

References