# CVE-2026-102893: Zulip: OpenID Connect authentication ignores the email_verified claim

> Attackers can hijack accounts if a misconfigured identity provider sends unverified emails, allowing login to existing accounts.

- **Severity:** Critical 9.1 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-xw9h-9rcm-hx4m

## What is CVE-2026-102893?

CVE-2026-102893 is a critical authentication bypass vulnerability in zulip, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Zulip is an open-source team collaboration tool. In Zulip Server versions through 12.1, GenericOpenIdConnectBackend matches the identity provider email claim to an active account's delivery_email without rejecting an explicitly false email_verified claim. If a configured identity provider returns an email address that the authenticating user does not control together with email_verified=false, Zulip can log the user into the existing account for that address. Exploitation requires a misconfigured trusted identity provider, and deployments whose authoritative identity provider only emits email addresses controlled by the authenticating user are not affected. This issue is fixed in version 12.2.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-102893?


## How do I fix CVE-2026-102893?

No fix has been published for CVE-2026-102893 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-102893 being exploited?

There is no known exploitation of CVE-2026-102893 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102893 and fix it if it is affected.

What it is: CVE-2026-102893 is a critical authentication bypass vulnerability in zulip, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-102893 in the wild and no public exploit code.

Affected product: zulip. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-102893/ (Markdown: https://insights.sbomify.com/CVE-2026-102893/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102893
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102893
- OSV: https://osv.dev/vulnerability/CVE-2026-102893

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-102893/
Summaries are generated and may contain mistakes; the official description above is the record.