Linux: Use of Uninitialized Resource
CVE-2025-38718 is a high-severity use of uninitialized resource vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions d0194e391bb493aa6cec56d177b14df6b29188d5, 03d0cc6889e02420125510b5444b570f4bbf53d5, cd0e92bb2b7542fb96397ffac639b4f5b099d0cb as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to d0194e391bb493aa6cec56d177b14df6b29188d5 or 03d0cc6889e02420125510b5444b570f4bbf53d5 or cd0e92bb2b7542fb96397ffac639b4f5b099d0cb or 4506bcaabe004d07be8ff09116a3024fbd6aa965, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.4.297 or 5.10.241 or 5.15.190 or 6.6.103, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 90017accff61ae89283ad9a51f9ac46ca01633fb up to, but not including, d0194e391bb493aa6cec56d177b14df6b29188d5; 90017accff61ae89283ad9a51f9ac46ca01633fb up to, but not including, 03d0cc6889e02420125510b5444b570f4bbf53d5; 90017accff61ae89283ad9a51f9ac46ca01633fb up to, but not including, cd0e92bb2b7542fb96397ffac639b4f5b099d0cb; 90017accff61ae89283ad9a51f9ac46ca01633fb up to, but not including, 4506bcaabe004d07be8ff09116a3024fbd6aa965; 90017accff61ae89283ad9a51f9ac46ca01633fb up to, but not including, ea094f38d387d1b0ded5dee4a3e5720aa4ce0139; 90017accff61ae89283ad9a51f9ac46ca01633fb up to, but not including, 7d757f17bc2ef2727994ffa6d5d6e4bc4789a770; 90017accff61ae89283ad9a51f9ac46ca01633fb up to, but not including, fc66772607101bd2030a4332b3bd0ea3b3605250; 90017accff61ae89283ad9a51f9ac46ca01633fb up to, but not including, 1bd5214ea681584c5886fea3ba03e49f93a43c0e; and 2 more ranges | d0194e391bb493aa6cec56d177b14df6b29188d5, 03d0cc6889e02420125510b5444b570f4bbf53d5, cd0e92bb2b7542fb96397ffac639b4f5b099d0cb, 4506bcaabe004d07be8ff09116a3024fbd6aa965, ea094f38d387d1b0ded5dee4a3e5720aa4ce0139, 7d757f17bc2ef2727994ffa6d5d6e4bc4789a770 |
| Linux | Linux Kernel | 4.8 up to, but not including, 5.4.297; 5.5 up to, but not including, 5.10.241; 5.11 up to, but not including, 5.15.190; 5.16 up to, but not including, 6.6.103; 6.7 up to, but not including, 6.12.43; 6.13 up to, but not including, 6.15.11; 6.16 up to, but not including, 6.16.2; 6.17 | 5.4.297, 5.10.241, 5.15.190, 6.6.103, 6.12.43, 6.15.11 |
| Debian | Debian Linux | 11.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: sctp: linearize cloned gso packets in sctp_rcv A cloned head skb still shares these frag skbs in fraglist with the original head skb. It's not safe to access these frag skbs. syzbot reported two use-of-uninitialized-memory bugs caused by this: BUG: KMSAN: uninit-value in sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211 sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211 sctp_assoc_bh_rcv+0x1a7/0xc50 net/sctp/associola.c:998 sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331 sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1122 __release_sock+0x1da/0x330 net/core/sock.c:3106 release_sock+0x6b/0x250 net/core/sock.c:3660 sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360 sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885 sctp_sendmsg+0x32b9/0x4a80 net/sctp/socket.c:2031 inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:718 [inline] and BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367 sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886 sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] This patch fixes it by linearizing cloned gso packets in sctp_rcv().
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Uninitialized Resource
The product uses or accesses a resource that has not been initialized.
How developers prevent this class of flaw
- Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
- Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
- Avoid race conditions (CWE-362) during initialization routines.
More Use of Uninitialized Resource vulnerabilities (CWE-908)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/03d0cc6889e02420125510b5444b570f4bbf53d5
- git.kernel.org/stable/c/1bd5214ea681584c5886fea3ba03e49f93a43c0e
- git.kernel.org/stable/c/4506bcaabe004d07be8ff09116a3024fbd6aa965
- git.kernel.org/stable/c/7d757f17bc2ef2727994ffa6d5d6e4bc4789a770
- git.kernel.org/stable/c/cd0e92bb2b7542fb96397ffac639b4f5b099d0cb
- git.kernel.org/stable/c/d0194e391bb493aa6cec56d177b14df6b29188d5
- git.kernel.org/stable/c/ea094f38d387d1b0ded5dee4a3e5720aa4ce0139
- git.kernel.org/stable/c/fc66772607101bd2030a4332b3bd0ea3b3605250
- git.kernel.org/stable/c/fd60d8a086191fe33c2d719732d2482052fa6805
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/10/msg00007.htmlMailing List, Third Party Advisory
Recent Use of Uninitialized Resource vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.1 High severity
- 7.5 High severity
- 8.8 High severity
- 7.8 High severity
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