# CVE-2026-98934: ipv6: sr: use skb_get_hash_net() in seg6_make_flowlabel()


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** AZL-110720, BELL-CVE-2026-98934, DEBIAN-CVE-2026-98934, GHSA-646v-44w7-2g7c, UBUNTU-CVE-2026-98934

## What is CVE-2026-98934?

CVE-2026-98934 is a vulnerability in Linux, published on 23 Oct 2026. 

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ipv6: sr: use skb_get_hash_net() in seg6_make_flowlabel()

Since commit d58e468b1112 ("flow_dissector: implements flow dissector
BPF hook") __skb_flow_dissect() needs a net pointer, either from
skb->dev, skb->sk, or since commit 3cbf4ffba5ee ("net: plumb network
namespace into __skb_flow_dissect") a caller provided pointer.

syzbot was able to reach seg6_make_flowlabel() with an skb having
neither skb->dev nor skb->sk set: a TIPC UDP bearer sends a discovery
message through an IPv4 route using seg6 encap, while
net.ipv6.seg6_flowlabel is set to 1.

seg6_make_flowlabel() already has a net pointer, use skb_get_hash_net().

WARNING: net/core/flow_dissector.c:1131 at __skb_flow_dissect+0x910/0x5368 net/core/flow_dissector.c:1126, CPU#0: syz.0.17/4930
Call trace:
  __skb_flow_dissect+0x910/0x5368 net/core/flow_dissector.c:1126 (P)
  __skb_get_hash_net+0xe0/0x29c net/core/flow_dissector.c:1903
  skb_get_hash include/linux/skbuff.h:1663 [inline]
  seg6_make_flowlabel+0xcc/0x1ec net/ipv6/seg6_iptunnel.c:132
  __seg6_do_srh_encap+0x320/0xbf4 net/ipv6/seg6_iptunnel.c:161
  seg6_do_srh+0x4b4/0xa44 net/ipv6/seg6_iptunnel.c:431
  seg6_output_core+0x164/0x688 net/ipv6/seg6_iptunnel.c:681
  seg6_output+0x44/0x1ac net/ipv6/seg6_iptunnel.c:744
  lwtunnel_output+0x3d0/0x664 net/core/lwtunnel.c:356
  dst_output include/net/dst.h:470 [inline]
  ip_local_out+0x110/0x148 net/ipv4/ip_output.c:131
  iptunnel_xmit+0x50c/0xd38 net/ipv4/ip_tunnel_core.c:97
  udp_tunnel_xmit_skb+0x220/0x348 net/ipv4/udp_tunnel_core.c:187
  tipc_udp_xmit+0x75c/0x9c0 net/tipc/udp_media.c:202
  tipc_udp_send_msg+0x214/0x374 net/tipc/udp_media.c:274
  tipc_bearer_xmit_skb+0x260/0x3b0 net/tipc/bearer.c:576
  tipc_enable_bearer net/tipc/bearer.c:366 [inline]
  __tipc_nl_bearer_enable+0xc90/0xfb0 net/tipc/bearer.c:1048
  tipc_nl_bearer_enable+0x2c/0x48 net/tipc/bearer.c:1057
  genl_family_rcv_msg_doit+0x1e4/0x2d4 net/netlink/genetlink.c:1114

## Which versions are affected by CVE-2026-98934?


## How do I fix CVE-2026-98934?

Upgrade to a fixed version.

## Is CVE-2026-98934 being exploited?

There is no known exploitation of CVE-2026-98934 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98934 and fix it if it is affected.

What it is: CVE-2026-98934 is a vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-98934 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-2026-98934/ (Markdown: https://insights.sbomify.com/CVE-2026-98934/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98934
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98934
- OSV: https://osv.dev/vulnerability/CVE-2026-98934

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98934/
Summaries are generated and may contain mistakes; the official description above is the record.