5.5

CVE-2025-39852: linux

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2025-39852DEBIAN-CVE-2025-39852
Published 19-09-2025Last modified 11-05-2026
Open JSON

Vulnerability summary

CVE-2025-39852 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 3.5% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.15%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 16 · Related 15
DSA-6008-1OPENSUSE-SU-2025:20081-1SUSE-SU-2025:21074-1SUSE-SU-2025:21139-1SUSE-SU-2025:21179-1SUSE-SU-2026:20560-1

Timeline

  1. 19-09-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: net/tcp: Fix socket memory leak in TCP-AO failure handling for IPv6 When tcp_ao_copy_all_matching() fails in tcp_v6_syn_recv_sock() it just exits the function. This ends up causing a memory-leak: unreferenced object 0xffff0000281a8200 (size 2496): comm "softirq", pid 0, jiffies 4295174684 hex dump (first 32 bytes): 7f 00 00 06 7f 00 00 06 00 00 00 00 cb a8 88 13 ................ 0a 00 03 61 00 00 00 00 00 00 00 00 00 00 00 00 ...a............ backtrace (crc 5ebdbe15): kmemleak_alloc+0x44/0xe0 kmem_cache_alloc_noprof+0x248/0x470 sk_prot_alloc+0x48/0x120 sk_clone_lock+0x38/0x3b0 inet_csk_clone_lock+0x34/0x150 tcp_create_openreq_child+0x3c/0x4a8 tcp_v6_syn_recv_sock+0x1c0/0x620 tcp_check_req+0x588/0x790 tcp_v6_rcv+0x5d0/0xc18 ip6_protocol_deliver_rcu+0x2d8/0x4c0 ip6_input_finish+0x74/0x148 ip6_input+0x50/0x118 ip6_sublist_rcv+0x2fc/0x3b0 ipv6_list_rcv+0x114/0x170 __netif_receive_skb_list_core+0x16c/0x200 netif_receive_skb_list_internal+0x1f0/0x2d0 This is because in tcp_v6_syn_recv_sock (and the IPv4 counterpart), when exiting upon error, inet_csk_prepare_forced_close() and tcp_done() need to be called. They make sure the newsk will end up being correctly free'd. tcp_v4_syn_recv_sock() makes this very clear by having the put_and_exit label that takes care of things. So, this patch here makes sure tcp_v4_syn_recv_sock and tcp_v6_syn_recv_sock have similar error-handling and thus fixes the leak for TCP-AO.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.15%

Chance of exploitation in the next 30 days

Percentile

4%

Versus all other CVEs

30-day change

0.00 pp

From 0.14% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.15%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu122 products
  • linux< 6.8.0-106.106
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.8.0-1050.53
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 06b22ef29591f625ef877ae00d82192938e29e60, < 46d33c878fc0b3d7570366b2c9912395b3f4e701 | ≥ 06b22ef29591f625ef877ae00d82192938e29e60, < 3d2b356d994a8801acb397cafd28b13672c37ab5 | ≥ 06b22ef29591f625ef877ae00d82192938e29e60, < fa390321aba0a54d0f7ae95ee4ecde1358bb9234 | 6.7
  • linux_kernel≥ 6.7, < 6.12.46 | ≥ 6.13, < 6.16.6 | 6.17:rc1 | 6.17:rc2 | 6.17:rc3 | 6.17:rc4
Debian1 product
  • linux< 6.12.48-1 | < 6.16.6-1

3 vendors · 125 products

References

17 links
Show all 17 references