# CVE-2026-90111: linux: In the Linux kernel, the following vulnerability has been resolved:  ip6mr: do not clone dst in ip6mr_cache_report()...

CVE-2026-90111 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-90111, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-90111
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 17, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  ip6mr: do not clone dst in ip6mr_cache_report()  IPv6 input attaches a non-refcounted (NOREF) dst to skbs under RCU. When an ingress multicast packet misses MFC lookup, ip6mr_cache_unresolved() places the skb onto the unresolved queue, escaping the receive-side RCU grace period.  If the underlying route is deleted and freed, and the MFC queue is later resolved with a wrong parent interface, ip6_mr_forward() invokes ip6mr_cache_report(..., MRT6MSG_WRONGMIF), which executes dst_clone(skb_dst(pkt)) on the freed dst entry, triggering a slab use-after-free.  Report packets queued to mroute6_sk (a raw socket) and netlink notifications do not require an attached dst entry.  Fix this by: 1. Removing dst_clone() in ip6mr_cache_report() and ensuring report skbs    do not hold a dst. 2. Dropping skb_dst before queuing unresolved skbs in    ip6mr_cache_unresolved(), matching the fact that multicast    forwarding resolves outgoing routes anew via ip6_route_output().

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-90111](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90111.md) | Sep 23, 2026 |
| Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-90111](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90111.md) | Sep 23, 2026 |

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Data as of 2026-11-08T19:12:23Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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