CVE-2026-43088
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel within PF_KEY export paths, where the last 4 bytes of the sockaddr_in6 structure remain uninitialized. This issue affects only certain PF_KEY messages that are not properly zeroed before being filled.
Risk Assessment
Uninitialized bytes may lead to unpredictable application behavior or exposure of sensitive information. Organizations should be aware of potential security risks associated with data.
Recommendation
It is recommended to update the Linux kernel to the latest version to eliminate this vulnerability. Additionally, monitor PF_KEY messages to ensure they are properly zeroed.
Original NVD description (English source)
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()`.