# CVE-2026-19508: RDK WebUI heap-based buffer overflow vulnerability

> Remote unauthenticated attackers can trigger heap-based buffer overflow in RDK-B WebUI via crafted requests, leading to denial of service or arbitrary code execution.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Aug 2026
- **Updated:** 27 Aug 2026
- **Also known as:** GHSA-p7m5-wh78-3h6h

## What is CVE-2026-19508?

CVE-2026-19508 is a critical memory corruption vulnerability in RDK-B WebUI, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Heap-based buffer overflow in the multipart form-data parser in `jst_post.c` in RDK-B WebUI `rdkb-2025q4-kirkstone.04.10.26` allows a remote unauthenticated attacker to cause memory corruption and denial of service, and potentially execute arbitrary code, via a crafted multipart/form-data request.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-19508?


## How do I fix CVE-2026-19508?

No fix has been published for CVE-2026-19508 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-19508 being exploited?

There is no known exploitation of CVE-2026-19508 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-19508 and fix it if it is affected.

What it is: CVE-2026-19508 is a critical memory corruption vulnerability in RDK-B WebUI, published on 19 Aug 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-2026-19508 in the wild and no public exploit code.

Affected product: RDK-B WebUI. 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-2026-19508/ (Markdown: https://insights.sbomify.com/CVE-2026-19508/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-19508
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-19508
- OSV: https://osv.dev/vulnerability/CVE-2026-19508

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-19508/
Summaries are generated and may contain mistakes; the official description above is the record.