# CVE-2025-68160: Heap out-of-bounds write in BIO_f_linebuffer on short writes

> Heap out-of-bounds write in OpenSSL's line-buffering filter can cause crashes and denial of service when specific non-default configurations are used.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Jan 2026
- **Updated:** 15 Oct 2026
- **Also known as:** ALPINE-CVE-2025-68160, AZL-75281, AZL-75780, AZL-75887, AZL-76125, AZL-76164, BELL-CVE-2025-68160, DEBIAN-CVE-2025-68160, ECHO-3df5-a3a2-6763, GHSA-g78j-46j5-97cr, JLSEC-2026-261, MINI-98q2-9f23-8398, MINI-cgrv-25qh-c2v4, MINI-rj3h-gp23-63xh, OESA-2026-1464, OESA-2026-1465, OESA-2026-1466, OESA-2026-1467, UBUNTU-CVE-2025-68160

## What is CVE-2025-68160?

CVE-2025-68160 is a medium-severity memory corruption vulnerability in Openssl Openssl, published on 27 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Issue summary: Writing large, newline-free data into a BIO chain using the
line-buffering filter where the next BIO performs short writes can trigger
a heap-based out-of-bounds write.

Impact summary: This out-of-bounds write can cause memory corruption which
typically results in a crash, leading to Denial of Service for an application.

The line-buffering BIO filter (BIO_f_linebuffer) is not used by default in
TLS/SSL data paths. In OpenSSL command-line applications, it is typically
only pushed onto stdout/stderr on VMS systems. Third-party applications that
explicitly use this filter with a BIO chain that can short-write and that
write large, newline-free data influenced by an attacker would be affected.
However, the circumstances where this could happen are unlikely to be under
attacker control, and BIO_f_linebuffer is unlikely to be handling non-curated
data controlled by an attacker. For that reason the issue was assessed as
Low severity.

The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue,
as the BIO implementation is outside the OpenSSL FIPS module boundary.

OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2025-68160?

It affects 1 product.


Products: Openssl Openssl.

## How do I fix CVE-2025-68160?

Apply the vendor's patch.

## Is CVE-2025-68160 being exploited?

There is no known exploitation of CVE-2025-68160 in the wild and no public exploit code.

## Other vulnerabilities in Openssl Openssl

- [CVE-2009-3245](https://insights.sbomify.com/CVE-2009-3245/): Null dereference in n/a (critical 10.0)
- [CVE-2006-3738](https://insights.sbomify.com/CVE-2006-3738/): Memory corruption in n/a (critical 10.0)
- [CVE-2026-63073](https://insights.sbomify.com/CVE-2026-63073/): Untrusted Sender DN Used as Format String in CMP Response Validation (critical 9.8)
- [CVE-2016-6309](https://insights.sbomify.com/CVE-2016-6309/): Use after free in n/a (critical 9.8)
- [CVE-2016-0799](https://insights.sbomify.com/CVE-2016-0799/): Integer overflow in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68160 and fix it if it is affected.

What it is: CVE-2025-68160 is a medium-severity memory corruption vulnerability in Openssl Openssl, published on 27 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-68160 in the wild and no public exploit code.

Affected product: Openssl Openssl. 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-2025-68160/ (Markdown: https://insights.sbomify.com/CVE-2025-68160/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68160
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68160
- OSV: https://osv.dev/vulnerability/CVE-2025-68160

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68160/
Summaries are generated and may contain mistakes; the official description above is the record.