Security readout for executives and security teams
Plain-English summary
Peppermint through version 0.5.5 publishes a fixed key used to prove login sessions are legitimate. An unauthenticated attacker who knows that key can impersonate any user, access protected functions, and potentially compromise the confidentiality, integrity, and availability of the application.
Executive priority
Treat this as an immediate remediation priority for affected deployments. A successful attacker could impersonate privileged users without passwords. Prioritize internet-accessible systems, rotate the secret, restrict access during response, investigate for suspicious activity, and follow vendor guidance before declaring closure.
Technical view
The bundled docker-compose.yml contains a hard-coded JWT signing secret. Because the API relies on that secret to validate session tokens, attackers can forge accepted tokens for arbitrary user IDs without credentials. The issue is classified as CWE-798 and carries CVSS 3.1 score 9.8.
Likely exposure
Highest risk applies to Peppermint deployments through 0.5.5 that used the bundled Docker Compose configuration and retained its published JWT secret. Deployments using an independently generated secret may not share this specific exposure. Internet-accessible instances have greater practical risk, but network exposure details are not provided.
Exploitation context
The attack requires no account, user interaction, or complex prerequisite, according to the supplied CVSS vector. The source bundle does not identify CISA KEV listing or provide evidence of active exploitation. However, the secret and affected configuration are publicly available, making attempted abuse plausible.
Researcher notes
The weakness is a secret-management failure rather than a JWT cryptographic flaw. Exposure depends on whether the deployed signing secret matches the public Compose value. The supplied sources establish affected versions through 0.5.5, but do not establish a fixed version, vendor patch, exploitation campaign, or complete token-lifetime behavior.
Mitigation direction
- Replace the published JWT secret with a unique, high-entropy value stored securely.
- Invalidate existing sessions or tokens after rotation where Peppermint supports doing so.
- Restrict network access to Peppermint until the secret is replaced and validation completes.
- Review vendor guidance for a fixed release or additional required remediation.
- Upgrade when the vendor identifies a release that resolves this vulnerability.
Validation and detection
- Inventory Peppermint instances and identify deployments running version 0.5.5 or earlier.
- Check deployed configuration for the published signing secret without copying it into reports or tickets.
- Confirm each instance uses a unique secret not inherited from the bundled Compose file.
- Verify tokens issued before rotation are rejected, where safe authorized testing is available.
- Review authentication and protected-endpoint logs for unexplained user IDs or anomalous access.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-798: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-85391 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.3CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- GitHub Issue #528CVE reference, VulnCheck · issue-tracking
- https://github.com/Peppermint-Lab/peppermintCVE reference, VulnCheck · product
- https://github.com/Peppermint-Lab/peppermint/blob/0.5.5/docker-compose.ymlCVE reference, VulnCheck · technical-description
- https://github.com/Peppermint-Lab/peppermint/blob/0.5.5/apps/api/src/lib/jwt.tsCVE reference, VulnCheck · technical-description
- VulnCheck Advisory: Peppermint through 0.5.5 Use of Hard-coded JWT Signing Secret in docker-compose.ymlCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use of Hard-coded Credentials
Use of Hard-coded Credentials represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.