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highAuth Bypass

CVE-2026-48508

CVE-2026-48508 — Lemur: Authorization bypass in StrictRolePermission / AuthorityCreatorPermission

Lemur manages TLS certificate creation. Prior to 1.9.1, StrictRolePermission and AuthorityCreatorPermission in lemur/auth/permissions.py call flask_principal.Permission.__init__() with zero Need objects when ADMIN_ONLY_AUTHORITY_CREATION and LEMUR_STRICT_ROLE_ENFORCEMENT are unset because both flags default to False. Flask-Principal Permission.allows() returns True when self.needs is empty, so the .can() authorization gate permits every authenticated identity, including the read-only role. A read-only user can access POST /api/1/authorities, POST /api/1/certificates/upload, POST /api/1/pending_certificates//upload, POST /api/1/notifications, PUT or DELETE /api/1/notifications/, and POST /api/1/domains to create root Certificate Authorities, upload arbitrary certificates, create or edit notifications that reach an SSRF sink, and create domain entries. Explicitly setting either flag to False continues to opt into the permissive behavior. This issue is fixed in version 1.9.1.

Published Updated Sources: NVD, Netflix (CNA), GitHub, GitHub Security Advisory, SOCRadar CTI

Triage

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

Exploitation

Unreported

no source claims exploitation

EPSS

0%

ahead of 11% of scored CVEs

Affects

Netflix

2 products listed

CVSS base

8.8

high

CISA SSVC assessment

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

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

No

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade lemur to 1.9.1 or later (pip advisory GHSA-qcqw-jwxc-2hqg).

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

  • Identify exposed assets running affected vendor/product/version combinations.
  • Prioritize based on EPSS, PoC availability, and external exposure.
  • Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

VendorProductVersionsStatus
Netflixlemur< 1.9.1Vulnerable
piplemur<= 1.9.0Vulnerable

Attack characteristics

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

Availability

High

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

Low

User Interaction

None

Every base score collected

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

ScoreVersionSeverityExpl.ImpactSource
8.8CVSS 3.1high2.85.9GitHub (CNA), Netflix (CNA), GHSA

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-863 · Incorrect Authorization

  • Read Application Data
  • Read Files or Directories
  • Modify Application Data
  • Modify Files or Directories

Mitigation: Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.

Weakness & attack patterns

  • CWE-863

Inferred from the weakness class — not observed against this CVE.

CAPEC-115 · Authentication BypassCAPEC-94 · Adversary in the Middle

Social mentions

Posts naming this CVE. Attention, not evidence of exploitation — it spikes on disclosure and decays whether or not anything is exploited.

Detection

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

  • Search application, proxy, and WAF logs for requests touching /auth/permissions.py, /api/1/authorities, /api/1/certificates/upload, /api/1/pending_certificates//upload, /api/1/notifications, /api/1/notifications/, /api/1/domains.
  • Prioritize edge telemetry for network-reachable lemur.
web/proxy/WAF logsapplication logsnetwork IDS/IPSidentity provider logsauthentication audit logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

  1. 2026
  2. Added · CVSS 3.1 8.8 (AV:N)

    Aug 18, 2026 · NVD

  3. Initial · CVE published

    Aug 18, 2026 · NVD

  4. Added · GHSA-qcqw-jwxc-2hqg published (high)

    Jun 25, 2026 · GitHub Security Advisory

Source activity

Readings a source repeats on a schedule, counted rather than listed.

  • Tweets · 1 time tweeted.Jun 26, 2026 · SOCRadar CTI
  • ModifiedAug 18, 2026 · SOCRadar CTI
  • SVRS is calculatedJun 26, 2026 · SOCRadar CTI

References

4 on the record

Elsewhere on this site

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 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 record1

What should defenders know first?

CVE-2026-48508 is Lemur: Authorization bypass in StrictRolePermission / AuthorityCreatorPermission, a high vulnerability affecting lemur from Netflix, pip. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-48508. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-48508. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 8.8 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.