製品・ソフトウェアに関する情報
Linuxカーネルにおける複数の脆弱性
Title Linuxカーネルにおける複数の脆弱性
Summary

CERT/CCから本件に関するアドバイザリが公表されました。 <ul><li><a href='https://kb.cert.org/vuls/id/980487' target='_blank'>VU#980487: Local privilege escalation in Linux Kernel (Dirty Frag)</a></li><li><a href='https://kb.cert.org/vuls/id/260001' target='_blank'>VU#260001: Linux kernel contains local privilege escalation vulnerability (Copy Fail)</a></li></ul>

Possible impacts 想定される影響は各脆弱性により異なりますが、次のような影響を受ける可能性があります。<ul><li>脆弱性を組み合わせることで、認証されたローカルのユーザによって、権限を昇格される(CVE-2026-43284、CVE-2026-43500)</li><li>認証されたローカルのユーザによって、権限を昇格される(CVE-2026-31431)</li></ul>
Solution

CERT/CCのアドバイザリを参照してください。

Publication Date May 25, 2026, midnight
Registration Date May 26, 2026, 2:07 p.m.
Last Update May 26, 2026, 2:07 p.m.
Affected System
Linux
Linux Kernel 
CVE (情報セキュリティ 共通脆弱性識別子)
その他
Change Log
No Changed Details Date of change
1 [2026年05月26日]
  掲載
May 26, 2026, 2:07 p.m.

NVD Vulnerability Information
CVE-2026-31431
Summary

In the Linux kernel, the following vulnerability has been resolved:

crypto: algif_aead - Revert to operating out-of-place

This mostly reverts commit 72548b093ee3 except for the copying of
the associated data.

There is no benefit in operating in-place in algif_aead since the
source and destination come from different mappings. Get rid of
all the complexity added for in-place operation and just copy the
AD directly.

Publication Date April 22, 2026, 6:16 p.m.
Registration Date April 25, 2026, 4:04 a.m.
Last Update April 27, 2026, 11:16 p.m.
Related information, measures and tools
Common Vulnerabilities List
CVE-2026-43284
Summary

In the Linux kernel, the following vulnerability has been resolved:

xfrm: esp: avoid in-place decrypt on shared skb frags

MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP
marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(),
so later paths that may modify packet data can first make a private
copy. The IPv4/IPv6 datagram append paths did not set this flag when
splicing pages into UDP skbs.

That leaves an ESP-in-UDP packet made from shared pipe pages looking
like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW
fast path for uncloned skbs without a frag_list and decrypts in place
over data that is not owned privately by the skb.

Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching
TCP. Also make ESP input fall back to skb_cow_data() when the flag is
present, so ESP does not decrypt externally backed frags in place.
Private nonlinear skb frags still use the existing fast path.

This intentionally does not change ESP output. In esp_output_head(),
the path that appends the ESP trailer to existing skb tailroom without
calling skb_cow_data() is not reachable for nonlinear skbs:
skb_tailroom() returns zero when skb->data_len is nonzero, while ESP
tailen is positive. Thus ESP output will either use the separate
destination-frag path or fall back to skb_cow_data().

Publication Date May 8, 2026, 5:16 p.m.
Registration Date May 9, 2026, 4:12 a.m.
Last Update May 15, 2026, 2:16 a.m.
Affected software configurations
Configuration1 or higher or less more than less than
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 4.11 5.10.255
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 5.12 5.15.205
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 5.16 6.1.171
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 6.2 6.6.138
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 6.7 6.12.87
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 6.13 6.18.28
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 7.0 7.0.5
Related information, measures and tools
Common Vulnerabilities List
CVE-2026-43500
Summary

In the Linux kernel, the following vulnerability has been resolved:

rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present

The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE
handler in rxrpc_verify_response() copy the skb to a linear one before
calling into the security ops only when skb_cloned() is true. An skb
that is not cloned but still carries externally-owned paged fragments
(e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via
__ip_append_data, or a chained skb_has_frag_list()) falls through to
the in-place decryption path, which binds the frag pages directly into
the AEAD/skcipher SGL via skb_to_sgvec().

Extend the gate to also unshare when skb_has_frag_list() or
skb_has_shared_frag() is true. This catches the splice-loopback vector
and other externally-shared frag sources while preserving the
zero-copy fast path for skbs whose frags are kernel-private (e.g. NIC
page_pool RX, GRO). The OOM/trace handling already in place is reused.

Publication Date May 11, 2026, 5:16 p.m.
Registration Date May 12, 2026, 4:13 a.m.
Last Update May 18, 2026, 1:16 a.m.
Affected software configurations
Configuration1 or higher or less more than less than
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 5.3 6.18.29
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 6.19 7.0.6
cpe:2.3:o:linux:linux_kernel:5.3:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.3:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.3:rc8:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
Related information, measures and tools
Common Vulnerabilities List