High Access control

CVE-2026-78553 — Insecure Flask Secret-Key File Permissions Allow Local Administrator Session Forgery in RansomLook

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.

Published Aug 24, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: CIRCL

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.2%

ahead of 9% of scored CVEs · Oct 14, 2026

Affects

Ransomlook

CVSS base

7.0

High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Ransomlook Ransomlook).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Ransomlook	Ransomlook	≤ 2.0.0	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Attack requirements

None

Privileges required

None

User interaction

None

Scope

Confidentiality (vulnerable system)

High

Integrity (vulnerable system)

Low

Availability (vulnerable system)

None

Confidentiality (subsequent)

None

Integrity (subsequent)

None

Availability (subsequent)

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.0	CVSS 4.0	High	—	—	5a6e4751-2f3f-4070-9419-94fb35b644e8 via NIST National Vulnerability Database
7.0	CVSS 4.0	High	—	—	CIRCL via CVE Program (cve.org) e CISA ADP

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/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

(score shown at the top: 5a6e4751-2f3f-4070-9419-94fb35b644e8)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-276 · Incorrect Default Permissions

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.20%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Audit administrative actions and access to resources outside each user’s normal pattern.

endpoint telemetry (EDR)authentication logsapplication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · ransomlook/ransomlook
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 7.0
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Deferred
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Aug 24, 2026 · CIRCL

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

github.com/RansomLook/RansomLook/commit/df9d47edcf02dd0125db869d5bc19d93f426d892
patch, NIST National Vulnerability Database

Elsewhere on this site

Ransomlook
every CVE for this vendor

Access control
same class

CWE-276
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-78555 RansomLook API Key Disclosure Through /admin/apikeys HTML Source Aug 24, 2026
High CVE-2026-78551 RansomLook Login Endpoint Allows Timing-Based Username Enumeration and Unthrottled Authentication Attempts Aug 24, 2026
Critical CVE-2026-78387 RansomLook Missing Authorization in Web Configuration Editor Allows Application Configuration Modification Aug 24, 2026
High CVE-2026-78391 Stored Cross-Site Scripting via Untrusted Cryptocurrency Address Rendering in RansomLook Aug 24, 2026
High CVE-2026-78386 Unauthenticated Disclosure of Scraping Credentials and Bypass Configuration via RansomLook API Aug 24, 2026
Critical CVE-2026-78370 RansomLook Unauthenticated Database Export Exposes Private Data Aug 24, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-78553 is "Insecure Flask Secret-Key File Permissions Allow Local Administrator Session Forgery in RansomLook", rated High. It affects Ransomlook (Ransomlook); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.0 describes technical severity. EPSS 0.20% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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