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VulnerabilityPublished Updated

CVE-2026-53096: Linux kernel · bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in d4c4bd231ebad70e6f30db429e9640bf378b2f52 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in d4c4bd231ebad70e6f30db429e9640bf378b2f52, cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a, b089aa6e94d7a08e74d076a0fe274842dc9feccc +4
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 24 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ e624d4ed4aa8cc3c69d1359b0aaea539203ed266, < d4c4bd231ebad70e6f30db429e9640bf378b2f52
Fixed in
  • d4c4bd231ebad70e6f30db429e9640bf378b2f52
LinuxLinuxAffected
  • ≥ e624d4ed4aa8cc3c69d1359b0aaea539203ed266, < cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a
Fixed in
  • cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a
LinuxLinuxAffected
  • ≥ e624d4ed4aa8cc3c69d1359b0aaea539203ed266, < b089aa6e94d7a08e74d076a0fe274842dc9feccc
Fixed in
  • b089aa6e94d7a08e74d076a0fe274842dc9feccc
LinuxLinuxAffected
  • ≥ e624d4ed4aa8cc3c69d1359b0aaea539203ed266, < 7027e705062482a8cea43a1c13ede3c35653966f
Fixed in
  • 7027e705062482a8cea43a1c13ede3c35653966f
LinuxLinuxAffected
  • ≥ e624d4ed4aa8cc3c69d1359b0aaea539203ed266, < 571a05ea1baaccc0dc1e0d227b2cbc978b96d392
Fixed in
  • 571a05ea1baaccc0dc1e0d227b2cbc978b96d392
LinuxLinuxAffected
  • ≥ e624d4ed4aa8cc3c69d1359b0aaea539203ed266, < 8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19
Fixed in
  • 8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path The DEVMAP_HASH branch in dev_map_redirect_multi() uses hlist_for_each_entry_safe() to iterate hash buckets, but this function runs under RCU protection (called from xdp_do_generic_redirect_map() in softirq context). Concurrent writers (__dev_map_hash_update_elem, dev_map_hash_delete_elem) modify the list using RCU primitives (hlist_add_head_rcu, hlist_del_rcu). hlist_for_each_entry_safe() performs plain pointer dereferences without rcu_dereference(), missing the acquire barrier needed to pair with writers' rcu_assign_pointer(). On weakly-ordered architectures (ARM64, POWER), a reader can observe a partially-constructed node. It also defeats CONFIG_PROVE_RCU lockdep validation and KCSAN data-race detection. Replace with hlist_for_each_entry_rcu() using rcu_read_lock_bh_held() as the lockdep condition, consistent with the rcu_dereference_check() used in the DEVMAP (non-hash) branch of the same functions. Also fix the same incorrect lockdep_is_held(&dtab->index_lock) condition in dev_map_enqueue_multi(), where the lock is not held either.

References

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