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CVE-2026-72404

HIGH 7.8 ALL-YEARS

Published 2026-08-15 · Last modified 2026-10-21 · Linux · NVD: Received

In the Linux kernel, the following vulnerability has been resolved: tipc: fix UAF in cleanup_bearer() due to premature dst_cache_destroy() TIPC UDP media bearer teardown calls dst_cache_destroy() on its replicast caches before calling synchronize_net() to wait for concurrent RCU readers (transmitters) to finish: static void cleanup_bearer(struct work_struct *work) { ... list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) { dst_cache_destroy(&rcast->dst_cache); list_del_rcu(&rcast->list); kfree_rcu(rcast, rcu); } ... dst_cache_destroy(&ub->rcast.dst_cache); udp_tunnel_sock_release(ub->sk); synchronize_net(); ... } This is highly buggy because dst_cache_destroy() immediately frees the per-CPU cache memory (free_percpu()) and releases the cached dst entries without any synchronization. If a concurrent transmitter (e.g., tipc_udp_xmit()) is running on another CPU under RCU protection, it can call dst_cache_get() concurrently, leading to: 1. Use-After-Free on the per-CPU cache pointer itself (crash). 2. "rcuref - imbalanced put()" warning if it attempts to release a dst that was concurrently released by dst_cache_destroy(). Furthermore, calling kfree(ub) immediately after synchronize_net() without closing the socket first (or waiting after closing it) leaves a window where a concurrent receiver (tipc_udp_recv()) could start after synchronize_net(), access ub, and suffer a UAF when kfree(ub) runs. To fix this, we must defer dst_cache_destroy() and kfree

ELEVATED IMPACT

Severe if exploited (CVSS 7.8), but no confirmed exploitation. Patch on a normal cadence.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 5th percentile

○ In CISA KEV○ Catalogued PoC◆ SSVC: exploitation none, automatable no

Impact if exploited

7.8CVSS 3.1 · HIGH · CNA

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ⚠Access: Requires local access to the host
  • ⚠Privileges: Requires a low-privilege account
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

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Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Affected

Vendors Linux

Products Linux

Weakness (CWE)

Not classified.

CVSS vector

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

References and research data (JSON)

Vendor product assessments

Showing 32 of 274 vendor product statements; 242 omitted. Read the full vendor advisory.

  • kernel as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-abi-stablelists as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-abi-stablelists

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-modules-extra-matched as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-modules-extra-matched

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-rt-debug as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-debug

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-uki-virt-addons as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-uki-virt-addons

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-modules as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-modules

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-rt-modules-internal as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-modules-internal

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • python3-perf as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/python3-perf

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-64k-modules as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-64k-modules

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-debug-modules-internal as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-debug-modules-internal

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-rt-64k as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-64k

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-rt-64k-modules-core as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-64k-modules-core

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-rt-devel as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-devel

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-zfcpdump as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-zfcpdump

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • rv as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/rv

    • none available: Fix deferred
    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-debug as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-debug

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-devel as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-devel

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-headers as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-headers

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel.src as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel?arch=src

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • bpftool as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/bpftool

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-abi-whitelists as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-abi-whitelists

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-debug-devel as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-debug-devel

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-headers as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-headers

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-rt as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-rt-debug-devel as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-debug-devel

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-rt-doc as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-doc

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-rt-trace-devel as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-trace-devel

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-tools as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-tools

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • kernel-tools-libs-devel as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-tools-libs-devel

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00
  • python-perf as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/python-perf

    Red Hat · CVE-2026-72404 · Updated 2026-08-19T17:41:43+00:00

All CVSS metrics

  • HIGH 7.8 v3.1 · CNA Primary
    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  • HIGH 7.8 v3.1 · NVD Secondary
    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Advisories

Technical & other

Sources: NVD · CVE.org · All sources and attribution · EPSS