CVE-2025-21875

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-03-27. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: None knownExposed: 0

A fix is available — apply it.

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

mptcp: always handle address removal under msk socket lock

Syzkaller reported a lockdep splat in the PM control path:

WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 sock_owned_by_me include/net/sock.h:1711 [inline] WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 msk_owned_by_me net/mptcp/protocol.h:363 [inline] WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 mptcp_pm_nl_addr_send_ack+0x57c/0x610 net/mptcp/pm_netlink.c:788 Modules linked in: CPU: 0 UID: 0 PID: 6693 Comm: syz.0.205 Not tainted 6.14.0-rc2-syzkaller-00303-gad1b832bf1cf #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:sock_owned_by_me include/net/sock.h:1711 [inline] RIP: 0010:msk_owned_by_me net/mptcp/protocol.h:363 [inline] RIP: 0010:mptcp_pm_nl_addr_send_ack+0x57c/0x610 net/mptcp/pm_netlink.c:788 Code: 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 ca 7b d3 f5 eb b9 e8 c3 7b d3 f5 90 0f 0b 90 e9 dd fb ff ff e8 b5 7b d3 f5 90 <0f> 0b 90 e9 3e fb ff ff 44 89 f1 80 e1 07 38 c1 0f 8c eb fb ff ff RSP: 0000:ffffc900034f6f60 EFLAGS: 00010283 RAX: ffffffff8bee3c2b RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc90004d42000 RSI: 000000000000a407 RDI: 000000000000a408 RBP: ffffc900034f7030 R08: ffffffff8bee37f6 R09: 0100000000000000 R10: dffffc0000000000 R11: ffffed100bcc62e4 R12: ffff88805e6316e0 R13: ffff88805e630c00 R14: dffffc0000000000 R15: ffff88805e630c00 FS: 00007f7e9a7e96c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fd18ff8 CR3: 0000000032c24000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mptcp_pm_remove_addr+0x103/0x1d0 net/mptcp/pm.c:59 mptcp_pm_remove_anno_addr+0x1f4/0x2f0 net/mptcp/pm_netlink.c:1486 mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_netlink.c:1518 [inline] mptcp_pm_nl_del_addr_doit+0x118d/0x1af0 net/mptcp/pm_netlink.c:1629 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xb1f/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2543 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:733 ____sys_sendmsg+0x53a/0x860 net/socket.c:2573 ___sys_sendmsg net/socket.c:2627 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2659 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7e9998cde9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7e9a7e9038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7e99ba5fa0 RCX: 00007f7e9998cde9 RDX: 000000002000c094 RSI: 0000400000000000 RDI: 0000000000000007 RBP: 00007f7e99a0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7e99ba5fa0 R15: 00007fff49231088

Indeed the PM can try to send a RM_ADDR over a msk without acquiring first the msk socket lock.

The bugged code-path comes from an early optimization: when there are no subflows, the PM should (usually) not send RM_ADDR notifications.

The above statement is incorrect, as without locks another process could concur ---truncated---

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity55% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

March 27, 2025

Last Modified

August 5, 2026

Advisory Details (10)

Auto-updated Jul 17, 2026
Patch available.
generic

SSA-019113

https://cert-portal.siemens.com/productcert/html/ssa-019113.html
generic Patch Available

[SECURITY] [DLA 4193-1] linux-6.1 security update

https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
generic Patch Available

[SECURITY] [DLA 4178-1] linux security update

https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
generic

mptcp: always handle address removal under msk socket lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f865c24bc55158313d5779fc81116023a6940ca3
generic

mptcp: always handle address removal under msk socket lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a05da2be18aae7e82572f8d795f41bb49f5dfc7d
generic

mptcp: always handle address removal under msk socket lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8116fb4acd5d3f06cd37f84887dbe962b6703b1c
generic

mptcp: always handle address removal under msk socket lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7cca31035c05819643ffb5d7518e9a331b3f6651
generic

mptcp: always handle address removal under msk socket lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/494ec285535632732eaa5786297a9ae4f731b5ff
generic

mptcp: always handle address removal under msk socket lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4124b782ec2b1e2e490cf0bbf10f53dfd3479890
generic

mptcp: always handle address removal under msk socket lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2c3de6dff4373f1036e003f49a32629359530bdb

Vendor Advisories for CVE-2025-21875(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(31)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-hwe-24.04-edge (6.11.0-26.26~24.04.1) @ noble2026-05-30ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1083.92~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-fips (5.15.0.140.80) @ jammy2026-05-30ubuntu
ubuntulinux-tools-oracle-64k (6.11.0-1016.17) @ oracular2026-05-30ubuntu
ubuntulinux-tools-raspi-nolpae (5.15.0.1078.76) @ jammy2026-05-30ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.140.135) @ jammy2026-05-30ubuntu
ubuntulinux-tools-gcp-lts-22.04 (5.15.0.1083.79) @ jammy2026-05-30ubuntu
ubuntulinux-tools-gcp-fips (5.15.0.1083.73) @ jammy2026-05-30ubuntu
ubuntulinux-tools-aws (6.11.0-1014.15) @ oracular2026-05-30ubuntu
ubuntulinux-tools-gke-5.15 (5.15.0.1081.80) @ jammy2026-05-30ubuntu
ubuntulinux-tools-azure-fips (5.15.0.1089.74) @ jammy2026-05-30ubuntu
ubuntulinux-tools-aws-fips (5.15.0.1084.80) @ jammy2026-05-30ubuntu
ubuntulinux-tools-nvidia-tegra-rt (5.15.0.1037.37) @ jammy2026-05-30ubuntu
ubuntulinux-xilinx-zynqmp-tools-host (5.15.0-1050.54) @ jammy2026-05-30ubuntu
ubuntulinux-tools-realtime (5.15.0.1084.88) @ jammy2026-05-30ubuntu
ubuntulinux-virtual-6.8 (6.8.0-84.84) @ noble2026-05-30ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.142.152~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-aws-edge (5.15.0.1084.91~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1039.42.1) @ noble2026-05-30ubuntu
ubuntulinux-tools-gcp-edge (6.8.0-1040.42~22.04.1) @ jammy2026-05-30ubuntu
ubuntulinux-tools-realtime-hwe-22.04 (6.8.1-1034.35~22.04.1) @ jammy2026-05-30ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-84.84~22.04.1) @ jammy2026-05-30ubuntu
ubuntulinux-tools-realtime-6.8.1 (6.8.1-1034.35) @ noble2026-05-30ubuntu
ubuntulinux-tools-raspi-6.8 (6.8.0-1039.43) @ noble2026-05-30ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-85.85~22.04.1) @ jammy2026-05-30ubuntu
ubuntulinux-tools-ibm-lts-24.04 (6.8.0-1037.37) @ noble2026-05-30ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2031.32) @ noble2026-05-30ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1038.44) @ noble2026-05-30ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1037.38) @ noble2026-05-30ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1037.38~22.04.1) @ jammy2026-05-30ubuntu
linuxKernel @ 5.10.235—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

All Vendor Advisories

(25)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 10× in last 7d / 46× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 116 total refreshes for this CVE.

  1. 2026-08-07 16:26 UTCEPSS rescore
  2. 2026-08-06 13:46 UTCEPSS rescore
  3. 2026-08-05 19:16 UTCEPSS rescore
  4. 2026-08-05 14:01 UTCEG score recompute
  5. 2026-08-05 14:01 UTCVendor advisory
  6. 2026-08-05 14:01 UTCGHSA enrichment
  7. 2026-08-04 15:09 UTCEPSS rescore
  8. 2026-08-04 10:37 UTCEPSS rescore
  9. 2026-08-03 10:35 UTCEPSS rescore
  10. 2026-08-02 02:25 UTCEPSS rescore
  11. 2026-08-01 04:15 UTCEPSS rescore
  12. 2026-07-30 16:27 UTCEPSS rescore
  13. 2026-07-30 07:19 UTCEG score recompute
  14. 2026-07-30 07:19 UTCGHSA enrichment
  15. 2026-07-30 01:29 UTCEPSS rescore
  16. 2026-07-28 15:35 UTCEPSS rescore
  17. 2026-07-27 14:12 UTCEPSS rescore
  18. 2026-07-26 14:53 UTCEPSS rescore
  19. 2026-07-25 14:17 UTCEPSS rescore
  20. 2026-07-24 10:41 UTCOSV refresh
  21. 2026-07-23 14:17 UTCEPSS rescore
  22. 2026-07-23 02:50 UTCEG score recompute
  23. 2026-07-22 14:07 UTCEPSS rescore
  24. 2026-07-22 14:07 UTCEPSS rescore
  25. 2026-07-21 15:24 UTCEPSS rescore
Show 75 more
  1. 2026-07-20 17:07 UTCEPSS rescore
  2. 2026-07-19 14:30 UTCEPSS rescore
  3. 2026-07-19 14:30 UTCEPSS rescore
  4. 2026-07-19 02:28 UTCEPSS rescore
  5. 2026-07-19 02:28 UTCEPSS rescore
  6. 2026-07-18 10:03 UTCEPSS rescore
  7. 2026-07-16 17:02 UTCEPSS rescore
  8. 2026-07-15 16:57 UTCEPSS rescore
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 01:59 UTCEPSS rescore
  11. 2026-07-14 13:19 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  12. 2026-07-14 13:11 UTCMITRE cvelistV5
  13. 2026-07-13 22:29 UTCEPSS rescore
  14. 2026-07-13 22:29 UTCEPSS rescore
  15. 2026-07-13 06:12 UTCEPSS rescore
  16. 2026-07-13 06:12 UTCEPSS rescore
  17. 2026-07-12 05:46 UTCEPSS rescore
  18. 2026-07-12 05:46 UTCEPSS rescore
  19. 2026-07-11 08:27 UTCEPSS rescore
  20. 2026-07-11 08:26 UTCEPSS rescore
  21. 2026-07-09 19:09 UTCEPSS rescore
  22. 2026-07-08 15:14 UTCEPSS rescore
  23. 2026-07-07 13:45 UTCEPSS rescore
  24. 2026-07-07 06:21 UTCOSV refresh
  25. 2026-07-06 16:26 UTCEPSS rescore
  26. 2026-07-06 02:22 UTCEPSS rescore
  27. 2026-07-06 02:22 UTCEPSS rescore
  28. 2026-07-05 02:30 UTCEPSS rescore
  29. 2026-07-04 06:30 UTCEPSS rescore
  30. 2026-07-01 15:06 UTCEPSS rescore
  31. 2026-06-30 23:21 UTCEPSS rescore
  32. 2026-06-30 23:21 UTCEPSS rescore
  33. 2026-06-29 14:06 UTCEPSS rescore
  34. 2026-06-28 14:07 UTCEPSS rescore
  35. 2026-06-28 14:07 UTCEPSS rescore
  36. 2026-06-28 04:55 UTCEPSS rescore
  37. 2026-06-28 04:55 UTCEPSS rescore
  38. 2026-06-27 03:08 UTCEPSS rescore
  39. 2026-06-27 03:08 UTCEPSS rescore
  40. 2026-06-25 13:49 UTCEPSS rescore
  41. 2026-06-25 13:49 UTCEPSS rescore
  42. 2026-06-24 14:04 UTCEPSS rescore
  43. 2026-06-24 14:04 UTCEPSS rescore
  44. 2026-06-23 21:32 UTCEPSS rescore
  45. 2026-06-23 21:32 UTCEPSS rescore
  46. 2026-06-22 14:25 UTCEPSS rescore
  47. 2026-06-22 14:25 UTCEPSS rescore
  48. 2026-06-21 14:56 UTCEPSS rescore
  49. 2026-06-21 14:56 UTCEPSS rescore
  50. 2026-06-21 01:59 UTCEPSS rescore
  51. 2026-06-21 01:59 UTCEPSS rescore
  52. 2026-06-19 19:25 UTCEPSS rescore
  53. 2026-06-19 19:25 UTCEPSS rescore
  54. 2026-06-18 17:52 UTCEPSS rescore
  55. 2026-06-18 17:52 UTCEPSS rescore
  56. 2026-06-18 17:35 UTCOSV refresh
  57. 2026-06-17 17:52 UTCEPSS rescore
  58. 2026-06-16 17:52 UTCEPSS rescore
  59. 2026-06-16 17:52 UTCEPSS rescore
  60. 2026-06-15 17:48 UTCEPSS rescore
  61. 2026-06-14 23:17 UTCEPSS rescore
  62. 2026-06-13 22:59 UTCEPSS rescore
  63. 2026-06-12 23:11 UTCEPSS rescore
  64. 2026-06-11 13:59 UTCEPSS rescore
  65. 2026-06-10 22:18 UTCEPSS rescore
  66. 2026-06-10 13:22 UTCEPSS rescore
  67. 2026-06-08 14:16 UTCEPSS rescore
  68. 2026-06-08 14:16 UTCEPSS rescore
  69. 2026-06-07 15:24 UTCEPSS rescore
  70. 2026-06-07 15:24 UTCEPSS rescore
  71. 2026-06-06 13:47 UTCEPSS rescore
  72. 2026-06-06 13:47 UTCEPSS rescore
  73. 2026-06-05 22:46 UTCEPSS rescore
  74. 2026-06-05 22:46 UTCEPSS rescore
  75. 2026-06-05 06:10 UTCEPSS rescore

Related CVEs(same product + same vendor)

Frequently asked(5)

What is CVE-2025-21875?
CVE-2025-21875 is a medium vulnerability published on March 27, 2025. In the Linux kernel, the following vulnerability has been resolved: mptcp: always handle address removal under msk socket lock Syzkaller reported a lockdep splat in the PM control path: WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 sockownedby_me include/net/sock.h:1711 [inline] WARNING:…
When was CVE-2025-21875 disclosed?
CVE-2025-21875 was first published in the National Vulnerability Database on March 27, 2025, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-21875 actively exploited?
CVE-2025-21875 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 88.4% of all scored CVEs.
What is the CVSS score of CVE-2025-21875?
CVE-2025-21875 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-21875?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21875, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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