# CVE-2026-110257: OW2 ASM 5.0 before 9.11 Excessive Memory Allocation via BootstrapMethods Attribute

> Attackers can crash the JVM or consuming thread by supplying a crafted class file that triggers excessive memory allocation in the ASM library.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 14 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** AZL-108378, AZL-108426, DEBIAN-CVE-2026-110257, GHSA-jv96-63p8-4rfx, UBUNTU-CVE-2026-110257

## What is CVE-2026-110257?

CVE-2026-110257 is a medium-severity denial of service vulnerability in OW2 ASM, published on 14 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

OW2 ASM 5.0 before 9.11 contains an excessive memory allocation vulnerability in ClassReader.readBootstrapMethodsAttribute() that sizes an int array from num_bootstrap_methods without validating attribute_length. Attackers can supply a crafted class file of about 100 bytes that forces roughly 2 GB allocation, causing an OutOfMemoryError that crashes the JVM or consuming thread.

Weakness: CWE-789 (Memory Allocation with Excessive Size Value)

## Which versions are affected by CVE-2026-110257?


## How do I fix CVE-2026-110257?

Upgrade to a fixed version.

## Is CVE-2026-110257 being exploited?

There is no known exploitation of CVE-2026-110257 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-110257 and fix it if it is affected.

What it is: CVE-2026-110257 is a medium-severity denial of service vulnerability in OW2 ASM, published on 14 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-110257 in the wild and no public exploit code.

Affected product: OW2 ASM. 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-2026-110257/ (Markdown: https://insights.sbomify.com/CVE-2026-110257/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-110257
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-110257
- OSV: https://osv.dev/vulnerability/CVE-2026-110257

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-110257/
Summaries are generated and may contain mistakes; the official description above is the record.