# CVE-2025-38718: sctp: linearize cloned gso packets in sctp_rcv > A use-after-free vulnerability in the Linux kernel SCTP implementation allows attackers to cause denial of service or disclose sensitive memory information. - **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`) - **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:** Yes - **Published:** 4 Sep 2025 - **Updated:** 5 Aug 2026 - **Also known as:** AZL-66788, AZL-73893, BELL-CVE-2025-38718, DEBIAN-CVE-2025-38718, GHSA-p9gg-wgfj-48p7, ROOT-OS-DEBIAN-11-CVE-2025-38718, ROOT-OS-DEBIAN-12-CVE-2025-38718, ROOT-OS-UBUNTU-2204-CVE-2025-38718, ROOT-OS-UBUNTU-2404-CVE-2025-38718, UBUNTU-CVE-2025-38718 ## What is CVE-2025-38718? CVE-2025-38718 is a high-severity use after free vulnerability in Debian Debian Linux, published on 4 Sep 2025. 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: 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(). Weakness: CWE-908 (Use of Uninitialized Resource) ## Which versions are affected by CVE-2025-38718? It affects 2 products. Products: Debian Debian Linux, Linux kernel. ## How do I fix CVE-2025-38718? Apply the vendor's patch. ## Is CVE-2025-38718 being exploited? There is no known exploitation of CVE-2025-38718 in the wild and no public exploit code. ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-38718 and fix it if it is affected. What it is: CVE-2025-38718 is a high-severity use after free vulnerability in Debian Debian Linux, published on 4 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2025-38718 in the wild and no public exploit code. Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-38718/ (Markdown: https://insights.sbomify.com/CVE-2025-38718/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38718 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38718 - OSV: https://osv.dev/vulnerability/CVE-2025-38718 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-38718/ Summaries are generated and may contain mistakes; the official description above is the record.