# CVE-2025-39880: libceph: fix invalid accesses to ceph_connection_v1_info

> A memory corruption flaw in the Linux kernel's Ceph client allows invalid memory access, potentially causing denial of service.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 23 Sep 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-67662, AZL-74936, BELL-CVE-2025-39880, DEBIAN-CVE-2025-39880, GHSA-f84f-657f-x94w, ROOT-OS-UBUNTU-2204-CVE-2025-39880, ROOT-OS-UBUNTU-2404-CVE-2025-39880, UBUNTU-CVE-2025-39880

## What is CVE-2025-39880?

CVE-2025-39880 is a critical memory corruption vulnerability in Debian Debian Linux, published on 23 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

libceph: fix invalid accesses to ceph_connection_v1_info

There is a place where generic code in messenger.c is reading and
another place where it is writing to con->v1 union member without
checking that the union member is active (i.e. msgr1 is in use).

On 64-bit systems, con->v1.auth_retry overlaps with con->v2.out_iter,
so such a read is almost guaranteed to return a bogus value instead of
0 when msgr2 is in use.  This ends up being fairly benign because the
side effect is just the invalidation of the authorizer and successive
fetching of new tickets.

con->v1.connect_seq overlaps with con->v2.conn_bufs and the fact that
it's being written to can cause more serious consequences, but luckily
it's not something that happens often.

Weakness: CWE-704 (Incorrect Type Conversion or Cast)

## Which versions are affected by CVE-2025-39880?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-39880?

Apply the vendor's patch.

## Is CVE-2025-39880 being exploited?

There is no known exploitation of CVE-2025-39880 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-39880 and fix it if it is affected.

What it is: CVE-2025-39880 is a critical memory corruption vulnerability in Debian Debian Linux, published on 23 Sep 2025. 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-2025-39880 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2025-39880/ (Markdown: https://insights.sbomify.com/CVE-2025-39880/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-39880
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-39880
- OSV: https://osv.dev/vulnerability/CVE-2025-39880

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-39880/
Summaries are generated and may contain mistakes; the official description above is the record.