# CVE-2026-11956: TwiN gatus OIDC Session Cookie oidc.go setSessionCookie missing secure attribute

> Attackers can intercept sensitive OIDC session cookies due to missing secure attributes, potentially leading to session hijacking.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jun 2026
- **Updated:** 11 Jun 2026
- **Also known as:** GHSA-wwqf-6p54-3cfq

## What is CVE-2026-11956?

CVE-2026-11956 is a medium-severity vulnerability in TwiN gatus, published on 11 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was determined in TwiN gatus 5.36.0. Impacted is the function setSessionCookie of the file security/oidc.go of the component OIDC Session Cookie Handler. Executing a manipulation can lead to sensitive cookie without secure attribute. The attack can be launched remotely. This attack is characterized by high complexity. The exploitability is considered difficult. The reported GitHub issue was closed with the label "not planned".

Weakness: CWE-614 (Sensitive Cookie in HTTPS Session Without 'Secure' Attribute), CWE-1004 (Sensitive Cookie Without 'HttpOnly' Flag)

## Which versions are affected by CVE-2026-11956?


## How do I fix CVE-2026-11956?

No fix has been published for CVE-2026-11956 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-11956 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-11956 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11956 and fix it if it is affected.

What it is: CVE-2026-11956 is a medium-severity vulnerability in TwiN gatus, published on 11 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-11956 exists.

Affected product: TwiN gatus. 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-2026-11956/ (Markdown: https://insights.sbomify.com/CVE-2026-11956/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11956
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11956
- OSV: https://osv.dev/vulnerability/CVE-2026-11956

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11956/
Summaries are generated and may contain mistakes; the official description above is the record.