{"id":"CVE-2025-39682","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ntls: fix handling of zero-length records on the rx_list\n\nEach recvmsg() call must process either\n - only contiguous DATA records (any number of them)\n - one non-DATA re…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ntls: fix handling of zero-length records on the rx_list\n\nEach recvmsg() call must process either\n - only contiguous DATA records (any number of them)\n - one non-DATA re…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-754"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 6.0, < 6.1.149","linux_kernel >= 6.2, < 6.6.103","linux_kernel >= 6.7, < 6.12.44","linux_kernel >= 6.13, < 6.16.4","linux_kernel = 6.17","debian_linux = 11.0","simatic_cn_4100_firmware < 5.0"],"patched":["linux_kernel 6.16.4","simatic_cn_4100_firmware 5.0"],"published":"2025-09-05","updated":"2026-09-21","sourceUpdated":"2026-09-21T12:00:36.613","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-39682","references":[{"url":"https://git.kernel.org/stable/c/2902c3ebcca52ca845c03182000e8d71d3a5196f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/29c0ce3c8cdb6dc5d61139c937f34cb888a6f42e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3439c15ae91a517cf3c650ea15a8987699416ad9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/62708b9452f8eb77513115b17c4f8d1a22ebf843","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c09dd3773b5950e9cfb6c9b9a5f6e36d06c62677","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-032379.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-39682","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-39682.json"},{"url":"https://access.redhat.com/security/cve/CVE-2025-39682"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2393511"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-39682"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39682"},{"url":"https://lore.kernel.org/linux-cve-announce/2025090545-CVE-2025-39682-ddab@gregkh/T"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog"},{"url":"https://access.redhat.com/errata/RHSA-2025:16904"},{"url":"https://access.redhat.com/errata/RHSA-2025:19224"},{"url":"https://access.redhat.com/errata/RHSA-2025:19104"},{"url":"https://access.redhat.com/errata/RHSA-2025:16880"},{"url":"https://access.redhat.com/errata/RHSA-2025:19223"}],"tags":["nvd","kev","in-the-wild","exploit-available","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.012,"epssPercentile":0.66357,"kev":true,"kevDateAdded":"2026-09-18","kevDueDate":"2026-09-21","kevRansomware":false,"exploited":true,"exploits":{"github":2,"githubRepos":["https://github.com/khoatran107/cve-2025-39682","https://github.com/suominen/CVE-2025-39682"],"checkedAt":"2026-09-21T15:27:24.536Z"},"exploitAvailable":true,"ssvc":{"exploitation":"active","automatable":"yes","technicalImpact":"total","timestamp":"2026-09-18T19:25:58.427206Z"},"scores":{"nvd":9.8,"vendor":7},"ingestedAt":"2026-09-18T14:43:13.025Z","slug":"CVE-2025-39682","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ntls: fix handling of zero-length records on the rx_list\n\nEach recvmsg() call must process either\n - only contiguous DATA records (any number of them)\n - one non-DATA record\n\nIf the next record has different type than what has already been\nprocessed we break out of the main processing loop. If the record\nhas already been decrypted (which may be the case for TLS 1.3 where\nwe don't know type until decryption) we queue the pending record\nto the rx_list. Next recvmsg() will pick it up from there.\n\nQueuing the skb to rx_list after zero-copy decrypt is not possible,\nsince in that case we decrypted directly to the user space buffer,\nand we don't have an skb to queue (darg.skb points to the ciphertext\nskb for access to metadata like length).\n\nOnly data records are allowed zero-copy, and we break the processing\nloop after each non-data record. So we should never zero-copy and\nthen find out that the record type has changed. The corner case\nwe missed is when the initial record comes from rx_list, and it's\nzero length.\n\n## Affected\n\n- `linux_kernel >= 6.0, < 6.1.149`\n- `linux_kernel >= 6.2, < 6.6.103`\n- `linux_kernel >= 6.7, < 6.12.44`\n- `linux_kernel >= 6.13, < 6.16.4`\n- `linux_kernel = 6.17`\n- `debian_linux = 11.0`\n- `simatic_cn_4100_firmware < 5.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.16.4`\n- `simatic_cn_4100_firmware 5.0`\n\n## Vendor advisories\n\n- **RHSA-2025:16904** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), Red Hat Enterprise Linux Real Time (v. 10) · released 2025-09-29 · [advisory](https://access.redhat.com/errata/RHSA-2025:16904)\n- **RHSA-2025:19224** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux BaseOS E4S (v.9.2) · released 2025-10-29 · [advisory](https://access.redhat.com/errata/RHSA-2025:19224)\n- **RHSA-2025:19104** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.4), Red Hat Enterprise Linux BaseOS EUS (v.9.4), Red Hat CodeReady Linux Builder EUS (v.9.4), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4), Red Hat Enterprise Linux Real Time EUS (v.9.4) · released 2025-10-27 · [advisory](https://access.redhat.com/errata/RHSA-2025:19104)\n- **RHSA-2025:16880** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2025-09-29 · [advisory](https://access.redhat.com/errata/RHSA-2025:16880)\n- **RHSA-2025:19223** · Red Hat · fixed in: Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2), Red Hat Enterprise Linux Real Time E4S (v.9.2) · released 2025-10-29 · [advisory](https://access.redhat.com/errata/RHSA-2025:19223)","depth":"hadal","depthScore":79,"depthScoreParts":{"impact":53.9,"likelihood":0.2,"exploitation":25,"ransomware":0},"changes":[{"seq":207604,"id":"CVE-2025-39682","ts":1789793911257,"field":"kev","old":"false","new":"true"},{"seq":207475,"id":"CVE-2025-39682","ts":1789761068965,"field":"exploited","old":"false","new":"true"}]}