# CVE-2018-13843: Denial of service in n/a

> A memory leak in HTSlib allows attackers to cause denial of service by exhausting system memory through repeated operations.

- **Severity:** High 7.5 (`CVSS:3.0/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:** 10 Jul 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-13843, GHSA-fqfp-r4jq-mf88

## What is CVE-2018-13843?

CVE-2018-13843 is a high-severity denial of service vulnerability in n/a, published on 10 Jul 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue has been found in HTSlib 1.8. It is a memory leak in bgzf_getline in bgzf.c. NOTE: the software maintainer's position is that the "failure to free memory" can be fixed in applications that use the HTSlib library (such as test/test_bgzf.c in the original report) and is not a library issue

Weakness: CWE-772 (Missing Release of Resource after Effective Lifetime)

## Which versions are affected by CVE-2018-13843?

It affects 1 product.


Products: Htslib Htslib.

## How do I fix CVE-2018-13843?

No fix published yet.

## Is CVE-2018-13843 being exploited?

There is no known exploitation of CVE-2018-13843 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-13845](https://insights.sbomify.com/CVE-2018-13845/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-1000206](https://insights.sbomify.com/CVE-2017-1000206/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-31962](https://insights.sbomify.com/CVE-2026-31962/): HTSlib CRAM reader has heap buffer overflow due to improper validation of input (high 8.8)
- [CVE-2026-31963](https://insights.sbomify.com/CVE-2026-31963/): HTSlib CRAM reader has heap buffer overflow due to improper validation of input (high 8.8)
- [CVE-2026-31968](https://insights.sbomify.com/CVE-2026-31968/): HTSlib CRAM decoder vulnerable to buffer overflow (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-13843 and fix it if it is affected.

What it is: CVE-2018-13843 is a high-severity denial of service vulnerability in n/a, published on 10 Jul 2018. 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-2018-13843 in the wild and no public exploit code.

Affected product: n/a. 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-2018-13843/ (Markdown: https://insights.sbomify.com/CVE-2018-13843/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-13843
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-13843
- OSV: https://osv.dev/vulnerability/CVE-2018-13843

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-13843/
Summaries are generated and may contain mistakes; the official description above is the record.