Cyber Resilience

CVE-2026-53603

Exposed Creds

Published
04 September 2026
Modified
04 September 2026
CVSS Score v4 7.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/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
EPSS Score 0.0020 10th percentile
Risk Priority 34 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-53603 is a high-severity Cleartext Storage of Sensitive Information (CWE-312) vulnerability. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Unsecured Credentials (T1552); ranked at the 10th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-28 (Protection of Information at Rest) and SC-8 (Transmission Confidentiality and Integrity) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. Prior to version 0.3.8, Operator session tokens are stored in plaintext in the operator_sessions table (the token column is the PRIMARY KEY). The session token is a 32-byte random…

more

hex value sent directly in a cookie and valid for 24 hours. Anyone who can read the database (backup, snapshot, file copy, or SQL-level disclosure) obtains every active session token and can hijack operator sessions directly, with no further authentication. This issue has been patched in version 0.3.8.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
T1552.001 Credentials In Files Credential Access
Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials.
T1552.004 Private Keys Credential Access
Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials.
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
T1021 Remote Services Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1078 Valid Accounts Stealth
Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-34270Shared CWE-312, CWE-522
CVE-2024-31415Shared CWE-312, CWE-522
CVE-2026-4387Shared CWE-312, CWE-522
CVE-2026-55885Shared CWE-312, CWE-522
CVE-2024-45744Shared CWE-312, CWE-522
CVE-2023-2335Shared CWE-312, CWE-522
CVE-2026-49379Shared CWE-522
CVE-2025-58741Shared CWE-522
CVE-2026-14354Shared CWE-522
CVE-2025-13164Shared CWE-522

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V14.2.8
  • V11.3.3

Mitigating Controls (NIST 800-53 r5) AI

SC-28 requires cryptographic or equivalent protection of sensitive data at rest, directly stopping cleartext storage in accessible resources.

Transmission confidentiality and integrity enforcement stops credentials from being sent in plaintext or without protection.

Authenticator management requires secure generation, storage, and distribution of credentials, directly stopping insecure methods.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.DS-01 full match
prevents

Encryption and cryptographic controls for data-at-rest directly prevent cleartext storage of sensitive information.

PR.DS-02 full match
prevents

Encrypting data-in-transit fully prevents interception of credentials in motion while only partially satisfying the broader data-protection outcome.

PR.AA-01 mostly match
prevents

Credential management practices directly reduce insecure storage/transmission but do not guarantee encryption or transport protection.

PR.AA-04 mostly match
prevents

Protecting identity assertions covers conveyance of credentials but is narrower than full credential lifecycle protection.

PR.AA-03 partial match
prevents

Authentication policies can enforce stronger credential handling yet address only verification, not storage or transit protection.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Requiring protected storage, transmission, and non-display of passwords prevents credentials from being stored or sent in clear text where they can be harvested by unauthorized actors.

prevents

Protecting secret and private keys against disclosure and unauthorized use decreases the exposure of credentials that are stored or transmitted in recoverable form.

prevents

Forbidding clear-text transmission and display of passwords, plus the use of stronger alternatives to passwords, prevents credentials from being obtained or reused by attackers.

prevents

Acceptable-use expectations that cover protection of credentials and information assets throughout their lifecycle discourage practices that expose or mishandle authentication material.

prevents

Contractual clauses that survive termination help ensure that credentials and other secrets are not retained or misused after employment ends.

prevents

Regular reminders about password security and personal accountability make users less likely to store or transmit credentials in cleartext or other unprotected forms.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248525 All OL 8 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at-rest protection. prevents CWE-312
Oracle Linux 9 (1 rule)
  • V-271756 OL 9 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. prevents CWE-312
RHEL 8 (1 rule)
  • V-230224 All RHEL 8 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. prevents CWE-312

References