CVE-2026-43088

CVE-2026-43088 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

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()`.

Frequently asked questions

What is CVE-2026-43088?
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()`.
How severe is CVE-2026-43088?
CVE-2026-43088 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-43088 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43088?
CVE-2026-43088 primarily affects Linux Linux Kernel. In total, 13 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-43088?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-43088 have an EU (EUVD) identifier?
Yes. CVE-2026-43088 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27586.
When was CVE-2026-43088 published?
CVE-2026-43088 was published on 2026-05-06 and last updated on 2026-06-19.

References

Affected products (13)

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