# CVE-2026-86849: DPDK vhost-crypto integer overflow in lib/vhost

Source: https://junglewise.ai/threats/cve-2026-86849-a-flaw-was-found-in-dpdk-lib-vhost-vhost-crypto-integer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-14. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-86849 · Severity: medium · CVSS 6.5 · Published 2026-10-14

DPDK is a data plane library used in high-performance networking systems. A buffer overflow flaw in the vhost-crypto backend can be triggered by untrusted guest virtual machines to crash the host system or potentially cause other system instability. The vulnerability requires local access and low privileges to exploit.

Technologies: [DPDK](https://junglewise.ai/threats/technologies/dpdk). Vendors: [DPDK](https://junglewise.ai/threats/vendors/dpdk).

## Quick answers

**Is CVE-2026-86849 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86849 being exploited in the wild.

**How severe is CVE-2026-86849?** Medium severity, with a CVSS score of 6.5, published 14 October 2026.

**Which products and versions are affected?** DPDK <UNKNOWN>.

**Is there a fix for CVE-2026-86849?** No fixed version is recorded yet. Do not attach a virtio-crypto vhost-user backend to untrusted guests. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-86849 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-86849?** Check whether you run DPDK at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix


Do not attach a virtio-crypto vhost-user backend to untrusted guests.

## Technical details

Integer overflow in chain length checks combined with missing length validation on the RSA path in lib/vhost vhost-crypto can cause a host buffer overflow. An attacker with a compromised guest VM that has access to a virtio-crypto vhost-user device can trigger this flaw; Red Hat rates it as having a Denial of Service and memory corruption impact (CWE-787: Out-of-bounds Write).

## Affected products

- DPDK DPDK <UNKNOWN>

## Timeline

- 2026-10-14: disclosed

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-86849](https://access.redhat.com/security/cve/CVE-2026-86849)

## Related threats

- [DPDK vhost-crypto indirect-descriptor double-fetch out-of-bounds](https://junglewise.ai/threats/cve-2026-86848-a-flaw-was-found-in-dpdk-lib-vhost-vhost-crypto-the-indirect)
- [DPDK vhost-crypto uninitialized pointer in write-back chain](https://junglewise.ai/threats/cve-2026-86847-a-flaw-was-found-in-dpdk-lib-vhost-vhost-crypto-write-back-chain)
- [DPDK vhost-crypto out-of-bounds write via unchecked descriptor index](https://junglewise.ai/threats/cve-2026-86846-a-flaw-was-found-in-dpdk-lib-vhost-vhost-crypto-a-guest-can)
- [DPDK lib/vhost use-after-free in VDUSE handler](https://junglewise.ai/threats/cve-2026-86567-a-flaw-was-found-in-dpdk-lib-vhost-the-vduse-handler-fails-to)
- [DPDK lib/vhost integer underflow in RX descriptor processing](https://junglewise.ai/threats/cve-2026-86566-a-flaw-was-found-in-dpdk-lib-vhost-a-guest-with-runt-rx)