# CVE-2026-74495: igbvf: Fix leak in TX DMA error cleanup

> A memory leak in the igbvf driver's TX DMA error handling can lead to resource exhaustion and 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:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-96299, BELL-CVE-2026-74495, DEBIAN-CVE-2026-74495, GHSA-7vcq-2p5f-22mh, UBUNTU-CVE-2026-74495

## What is CVE-2026-74495?

CVE-2026-74495 is a critical memory corruption vulnerability in Linux, published on 15 Aug 2026. 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:

igbvf: Fix leak in TX DMA error cleanup

If an error is encountered while mapping TX buffers, the driver should
unmap any buffers already mapped for that skb.

Because count is incremented before each frag mapping, it will always
match the correct number of unmappings needed when dma_error is reached.
Decrementing count before the while loop in dma_error causes an
off-by-one error. If any mapping was successful before an unsuccessful
mapping, exactly one DMA mapping (the head) would leak.

This bug was introduced by a 2010 fix for an endless loop in dma_error.
All other affected drivers have already been fixed.

## Which versions are affected by CVE-2026-74495?


## How do I fix CVE-2026-74495?

Apply the vendor's patch.

## Is CVE-2026-74495 being exploited?

There is no known exploitation of CVE-2026-74495 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74495 and fix it if it is affected.

What it is: CVE-2026-74495 is a critical memory corruption vulnerability in Linux, published on 15 Aug 2026. 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-2026-74495 in the wild and no public exploit code.

Affected product: 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-2026-74495/ (Markdown: https://insights.sbomify.com/CVE-2026-74495/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74495
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74495
- OSV: https://osv.dev/vulnerability/CVE-2026-74495

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74495/
Summaries are generated and may contain mistakes; the official description above is the record.