CVE-2026-78553

HIGHCVSS 7/10EPSS 0.14%

Last modified

CVE-2026-78553 is a high-severity vulnerability rated 7/10 on the CVSS scale. RansomLook created its Flask session-signing key without explicitly restricting the file permissions. The secret_key file was created using the process's default permissions and umask, resulting in permissions such as 0644 under a common 022 umask. EPSS estimates a 0.14% chance of exploitation in the next 30 days.

Description

RansomLook created its Flask session-signing key without explicitly restricting the file permissions. The secret_key file was created using the process's default permissions and umask, resulting in permissions such as 0644 under a common 022 umask. Consequently, other local users able to access the RansomLook home directory could read the application's cryptographic secret. The exposed key is security-critical because it is used to sign Flask session cookies and is also involved in the legacy API-key key derivation. An attacker who obtains the key can generate valid session cookies and impersonate an authenticated user, including an administrator. In LDAP configurations, exploitation may be particularly straightforward because the session user loader does not require the supplied username to correspond to an existing local user. Successful exploitation requires local access sufficient to read the improperly protected file, but can result in complete compromise of RansomLook's authentication and authorization controls. The patch creates new secret-key files atomically with permissions 0600 and also restricts permissions on existing key files during application startup.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
ransomlookransomlook<= 2.0.0

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-78553?
RansomLook created its Flask session-signing key without explicitly restricting the file permissions. The secret_key file was created using the process's default permissions and umask, resulting in permissions such as 0644 under a common 022 umask. Consequently, other local users able to access the RansomLook home directory could read the application's cryptographic secret. The exposed key is security-critical because it is used to sign Flask session cookies and is also involved in the legacy API-key key derivation. An attacker who obtains the key can generate valid session cookies and impersonate an authenticated user, including an administrator. In LDAP configurations, exploitation may be particularly straightforward because the session user loader does not require the supplied username to correspond to an existing local user. Successful exploitation requires local access sufficient to read the improperly protected file, but can result in complete compromise of RansomLook's authentication and authorization controls. The patch creates new secret-key files atomically with permissions 0600 and also restricts permissions on existing key files during application startup.
How severe is CVE-2026-78553?
CVE-2026-78553 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 0.14% probability of exploitation in the next 30 days.
How do I fix CVE-2026-78553?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST