# CVE-2026-59143: Memory corruption in Data::RoaringBitmap::Shared

> A local attacker can trigger an out-of-bounds read and potential crash in the Perl Data::RoaringBitmap::Shared library by manipulating the backing file.

- **Severity:** Medium 6.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Jul 2026
- **Updated:** 23 Jul 2026
- **Also known as:** GHSA-96m7-w48r-fx74

## What is CVE-2026-59143?

CVE-2026-59143 is a medium-severity memory corruption vulnerability in EGOR Data::RoaringBitmap::Shared, published on 21 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Data::RoaringBitmap::Shared versions before 0.02 for Perl allow an out-of-bounds read via an unvalidated container offset and cardinality in rb_contains_locked.

The attach-time validator rb_validate_header checks the header scalars and region layout against the file size, but does not validate the bucket contents it then trusts. rb_contains_locked forms a container pointer as pool + container_off * 8192 from a raw file-stored offset and then searches over a file-stored cardinality, neither bounded against the container pool capacity or the fixed 8192-byte slot size.

A local peer that can write the backing file can leave the header valid while poisoning a bucket, so the next membership query dereferences a file-controlled wild pointer and scans a file-controlled count, reading adjacent memory or crashing the process.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-59143?


## How do I fix CVE-2026-59143?

No fix has been published for CVE-2026-59143 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-59143 being exploited?

There is no known exploitation of CVE-2026-59143 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-59143 and fix it if it is affected.

What it is: CVE-2026-59143 is a medium-severity memory corruption vulnerability in EGOR Data::RoaringBitmap::Shared, published on 21 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-59143 in the wild and no public exploit code.

Affected product: EGOR Data::RoaringBitmap::Shared. 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-2026-59143/ (Markdown: https://insights.sbomify.com/CVE-2026-59143/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59143
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59143
- OSV: https://osv.dev/vulnerability/CVE-2026-59143

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-59143/
Summaries are generated and may contain mistakes; the official description above is the record.