CVE-2026-43088 net: af_key: zero aligned sockaddr tail in PF_KEY exports
An attacker can read uninitialized kernel memory via PF_KEY exports, potentially exposing sensitive data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43088?
CVE-2026-43088 is a medium-severity vulnerability in Linux kernel, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: af_key: zero aligned sockaddr tail in PF_KEY exports
PF_KEY export paths use `pfkey_sockaddr_size()` when reserving sockaddr payload space, so IPv6 addresses occupy 32 bytes on the wire. However, `pfkey_sockaddr_fill()` initializes only the first 28 bytes of `struct sockaddr_in6`, leaving the final 4 aligned bytes uninitialized.
Not every PF_KEY message is affected. The state and policy dump builders already zero the whole message buffer before filling the sockaddr payloads. Keep the fix to the export paths that still append aligned sockaddr payloads with plain `skb_put()`:
- `SADB_ACQUIRE` - `SADB_X_NAT_T_NEW_MAPPING` - `SADB_X_MIGRATE`
Fix those paths by clearing only the aligned sockaddr tail after `pfkey_sockaddr_fill()`.
Which versions are affected by CVE-2026-43088?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43088?
Apply the vendor's patch.
Is CVE-2026-43088 being exploited?
There is no known exploitation of CVE-2026-43088 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-85895, BELL-CVE-2026-43088, DEBIAN-CVE-2026-43088, GHSA-5858-6g3v-6hmr, ROOT-OS-DEBIAN-11-CVE-2026-43088, ROOT-OS-DEBIAN-12-CVE-2026-43088 and 4 more.