# CVE-2026-31640: linux: In the Linux kernel, the following vulnerability has been resolved:  rxrpc: Fix use of wrong skb when comparing queue...

CVE-2026-31640 is fixed in linux on 1 platform by DEBIAN-CVE-2026-31640 (version 6.19.13-1), released May 15, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-31640
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0043
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 24, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  rxrpc: Fix use of wrong skb when comparing queued RESP challenge serial  In rxrpc_post_response(), the code should be comparing the challenge serial number from the cached response before deciding to switch to a newer response, but looks at the newer packet private data instead, rendering the comparison always false.  Fix this by switching to look at the older packet.  Fix further[1] to substitute the new packet in place of the old one if newer and also to release whichever we don't use.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 6.19.13-1 | [DEBIAN-CVE-2026-31640](https://patchblox.com/security/data/fix/linux/debian-cve-2026-31640.md) | May 15, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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