CRITICAL: CVE-2026-31657 (CVSS 9.8) — multiple products

CVE: CVE-2026-31657

CVSS: 9.8 (3.1) — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: CRITICAL

Status: Critical advisory

Affected

_See vendor advisory_

Summary

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

batman-adv: hold claim backbone gateways by reference

batadv_bla_add_claim() can replace claim->backbone_gw and drop the old

gateway's last reference while readers still follow the pointer.

The netlink claim dump path dereferences claim->backbone_gw->orig and

takes claim->backbone_gw->crc_lock without pinning the underlying

backbone gateway. batadv_bla_check_claim() still has the same naked

pointer access pattern.

Reuse batadv_bla_claim_get_backbone_gw() in both readers so they operate

on a stable gateway reference until the read-side work is complete.

This keeps the dump and claim-check paths aligned with the lifetime

rules introduced for the other BLA claim readers.

Verified Sources

• NVD entry
• GitHub Advisory
• MITRE

References

• https://git.kernel.org/stable/c/1f2dc36c297d27733f1b380ea644cf15a361bd7b
• https://git.kernel.org/stable/c/2f55b58b5a0bbed192d60c444a45a49cdf1b545f
• https://git.kernel.org/stable/c/4dee4c0688443aaf5bbec74aa203c851d1d53c35
• https://git.kernel.org/stable/c/7962b522222628596ca9ecc8722efc95367aadbd
• https://git.kernel.org/stable/c/82d8701b2c930d0e96b0dbc9115a218d791cb0d2
• https://git.kernel.org/stable/c/f4858832ddef2f39f21e30b7226bbcd3c4b2bc96

---

_Validated by the Lyrie Threat Intelligence Pipeline — 3 independent sources confirmed before publication. No speculation._