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

> Read-only users can create root CAs and upload certificates due to a permission bypass when specific security flags are disabled.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Aug 2026
- **Updated:** 18 Aug 2026
- **Also known as:** GHSA-qcqw-jwxc-2hqg, PYSEC-2026-2588

## What is CVE-2026-48508?

CVE-2026-48508 is a high-severity missing authorization vulnerability in Netflix lemur, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-48508?

3 open source packages ship an affected version, including lemur.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `lemur` | PyPI | All versions | 1.9.1 |
| `lemur` | PyPI | All versions | 1.9.1 |
| `lemur` | PyPI | All versions | 1.9.1 |

## How do I fix CVE-2026-48508?

Upgrade lemur to 1.9.1 or later.

## Is CVE-2026-48508 being exploited?

There is no known exploitation of CVE-2026-48508 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48508 and fix it if it is affected.

What it is: CVE-2026-48508 is a high-severity missing authorization vulnerability in Netflix lemur, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-48508 in the wild and no public exploit code.

Affected packages and fixed versions:
- lemur (PyPI): affected all versions; fixed in 1.9.1
- lemur (PyPI): affected all versions; fixed in 1.9.1
- lemur (PyPI): affected all versions; fixed in 1.9.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-48508/ (Markdown: https://insights.sbomify.com/CVE-2026-48508/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48508
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48508
- OSV: https://osv.dev/vulnerability/CVE-2026-48508

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48508/
Summaries are generated and may contain mistakes; the official description above is the record.