# CVE-2026-104845: Seroval: Memory exhaustion via unchecked TypedArray length in JSON deserialization

> An attacker can cause memory exhaustion and denial of service in Seroval by providing a crafted JSON object with a large length value during deserialization.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** CLSA-2026-1791289714, CLSA-2026-1792286817, GHSA-jp82-f5mq-hwhp

## What is CVE-2026-104845?

CVE-2026-104845 is a high-severity denial of service vulnerability in lxsmnsyc seroval, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. Prior to 1.6.3, deserializeTypedArray in fromJSON and fromCrossJSON trusts a deserialized source value as an ArrayBuffer and does not bound the serialized element count. An attacker can provide a small untrusted JSON object with a large length value, causing the array-like TypedArray constructor to synchronously allocate the selected number of elements and exhaust CPU or memory while starving the event loop. The offset check does not reject the crafted source because source.byteLength is undefined. DataView reaches a similar unchecked cast but throws rather than allocating, and the issue has no identified confidentiality or integrity impact. This issue is fixed in version 1.6.3.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-104845?

2 open source packages ship an affected version, including seroval.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `seroval` | npm | All versions | 1.6.3 |
| `seroval` | npm | All versions | 1.6.3 |

## How do I fix CVE-2026-104845?

Upgrade seroval to 1.6.3 or later.

## Is CVE-2026-104845 being exploited?

There is no known exploitation of CVE-2026-104845 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104845 and fix it if it is affected.

What it is: CVE-2026-104845 is a high-severity denial of service vulnerability in lxsmnsyc seroval, published on 2 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-2026-104845 in the wild and no public exploit code.

Affected packages and fixed versions:
- seroval (npm): affected all versions; fixed in 1.6.3
- seroval (npm): affected all versions; fixed in 1.6.3

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-2026-104845/ (Markdown: https://insights.sbomify.com/CVE-2026-104845/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104845
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104845
- OSV: https://osv.dev/vulnerability/CVE-2026-104845

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104845/
Summaries are generated and may contain mistakes; the official description above is the record.