# CVE-2026-97436: dpaa2-switch: rework FDB management on the bridge leave path

CVE-2026-97436 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-97436, released September 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-97436
- Priority: Routine
- CVSS: 3.0 (Low)
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 24, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97436

## Description

In the Linux kernel, the following vulnerability has been resolved:  dpaa2-switch: rework FDB management on the bridge leave path  On bridge leave, the dpaa2_switch_port_set_fdb() function always allocates a new FDB for the port which is becoming standalone. In case no FDB is found, then the port leaving a bridge will continue to use the current one.  The above logic does not cover the case in which there are multiple bridges which have ports from the same DPSW instance. In this case, when the last port leaves bridge #1, it finds an unused FDB to switch to, but the old FDB is not marked as unused. Since the number of FDBs is equal to the number of DPSW interfaces, this will eventually lead to multiple ports sharing the same FDB.  Fix this by changing how we are managing the FDBs on the leave path. Instead of directly allocating a new FDB, first verify if the current port is the last one to leave a bridge. If this is the case, then continue to use the current FDB and only allocate another FDB if there are other ports remaining in the bridge.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.190-1 | [DEBIAN-CVE-2026-97436](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97436.md) | Sep 24, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-97436](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97436.md) | Sep 24, 2026 |
| Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-97436](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97436.md) | Sep 24, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.111-1~deb12u1 | [DEBIAN-CVE-2026-97436](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97436.md) | Sep 24, 2026 |

---

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

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.