What is CVE-2026-55163?

CVE-2026-55163 is Lemur: Privilege escalation via PUT /api/1/roles/ — non-admin role members can rewrite role membership. The supplied enrichment data classifies it as Privilege Esc mapped to CWE-863 CWE-863.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-55163. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-55163 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

1 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS, EDR process telemetry, host service logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-55163 using CVSS 6.3, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

Workarounds are not confirmed from current sources. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

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. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

mediumPrivilege Escpublic exploit

CVE-2026-55163

CVE-2026-55163 — Lemur: Privilege escalation via PUT /api/1/roles/<id> — non-admin role members can rewrite role membership

Lemur manages TLS certificate creation. Prior to 1.9.2, PUT /api/1/roles/ in lemur/roles/views.py:298 authorized updates with RoleMemberPermission(role_id), which allowed either an administrator or any existing member of the target role. The handler passed data["users"] and data["name"] to service.update, allowing a non-admin member to add or remove other users and rename the role. This enabled lateral privilege grants within roles that control certificate and authority access and could deny access by removing legitimate members. The DELETE handler already required admin_permission, confirming that the weaker PUT authorization was inconsistent. The fix applies the same administrator-only requirement to the PUT handler. This issue is fixed in version 1.9.2.

Published Aug 18, 2026Updated Aug 18, 2026Sources: 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

Exploit code

public exploit, none observed

EPSS

ahead of 0% of scored CVEs

Affects

Netflix

2 products listed

CVSS base

6.3

medium

Remediation

The vendor's own words where we have them.

Upgrade lemur to 1.9.2 or later (pip advisory GHSA-x3vf-mgxj-7785).

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.

Vendor	Product	Versions	Status
Netflix	lemur	< 1.9.2	Vulnerable
pip	lemur	<= 1.9.1	Vulnerable

Attack characteristics

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

Availability

Low

Confidentiality

Low

Integrity

Low

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.

Score	Version	Severity	Expl.	Impact	Source
6.3	CVSS 3.1	medium	2.8	3.4	GitHub (CNA), Netflix (CNA), GHSA

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

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-233 · Privilege EscalationCAPEC-69 · Target Programs with Elevated Privileges

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

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 /api/1/roles/, /roles/views.py:298.
Prioritize edge telemetry for network-reachable lemur.
Review endpoint telemetry for service binary replacement, suspicious service launches, or privilege changes tied to the affected agent.
Monitor for scanner or exploit-pattern traffic after 1 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPSEDR process telemetryhost service logs

Timeline

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

2026
Added · CVSS 3.1 6.3 (AV:N)
Aug 18, 2026 · NVD
Initial · CVE published
Aug 18, 2026 · NVD
Added · GHSA-x3vf-mgxj-7785 published (medium)
Jun 25, 2026 · GitHub Security Advisory

Source activity

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

2×ModifiedAug 18, 2026 · SOCRadar CTI

References

4 on the record

github.com/Netflix/lemur/commit/9523a3b9cb3170ec9f795162b8c60e1ad3c4f9ce
Exploit, Third Party Advisory, Mitre, NIST
github.com/Netflix/lemur/releases/tag/v1.9.2
Exploit, Third Party Advisory, Mitre, NIST
github.com/Netflix/lemur/security/advisories/GHSA-x3vf-mgxj-7785
Exploit, Third Party Advisory, Mitre, NIST
github.com/advisories/GHSA-x3vf-mgxj-7785
Exploit, Third Party Advisory

Elsewhere on this site

Netflixevery CVE for this vendor
pipevery CVE for this vendor
Privilege Escsame class
CWE-863other pages naming this weakness

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-2026-55163 is Lemur: Privilege escalation via PUT /api/1/roles/<id> — non-admin role members can rewrite role membership, a medium 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-2026-55163. Public exploit evidence is: 1 public PoC repositories reported; 0 marked weaponized in current dataset. 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 6.3 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.