CVE-2025-21706

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-02-27. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
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: pm: only set fullmesh for subflow endp

With the in-kernel path-manager, it is possible to change the 'fullmesh' flag. The code in mptcp_pm_nl_fullmesh() expects to change it only on 'subflow' endpoints, to recreate more or less subflows using the linked address.

Unfortunately, the set_flags() hook was a bit more permissive, and allowed 'implicit' endpoints to get the 'fullmesh' flag while it is not allowed before.

That's what syzbot found, triggering the following warning:

WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 __mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline] WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline] WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline] WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:2064 Modules linked in: CPU: 0 UID: 0 PID: 6499 Comm: syz.1.413 Not tainted 6.13.0-rc5-syzkaller-00172-gd1bf27c4e176 #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline] RIP: 0010:mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline] RIP: 0010:mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline] RIP: 0010:mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:2064 Code: 01 00 00 49 89 c5 e8 fb 45 e8 f5 e9 b8 fc ff ff e8 f1 45 e8 f5 4c 89 f7 be 03 00 00 00 e8 44 1d 0b f9 eb a0 e8 dd 45 e8 f5 90 <0f> 0b 90 e9 17 ff ff ff 89 d9 80 e1 07 38 c1 0f 8c c9 fc ff ff 48 RSP: 0018:ffffc9000d307240 EFLAGS: 00010293 RAX: ffffffff8bb72e03 RBX: 0000000000000000 RCX: ffff88807da88000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000d307430 R08: ffffffff8bb72cf0 R09: 1ffff1100b842a5e R10: dffffc0000000000 R11: ffffed100b842a5f R12: ffff88801e2e5ac0 R13: ffff88805c214800 R14: ffff88805c2152e8 R15: 1ffff1100b842a5d FS: 00005555619f6500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002840 CR3: 00000000247e6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2542 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2669 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: 0033:0x7f5fe8785d29 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:00007fff571f5558 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f5fe8975fa0 RCX: 00007f5fe8785d29 RDX: 0000000000000000 RSI: 0000000020000480 RDI: 0000000000000007 RBP: 00007f5fe8801b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5fe8975fa0 R14: 00007f5fe8975fa0 R15: 000000 ---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
11%
KEV
Not listed

Published

February 27, 2025

Last Modified

July 14, 2026

Advisory Details (7)

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 4102-1] linux-6.1 security update

https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
generic

mptcp: pm: only set fullmesh for subflow endp - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/de3b8d41d2547452c4cafb146d003fa4689fbaf2
generic

mptcp: pm: only set fullmesh for subflow endp - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9e3d61620a3cd033319553b980ff3a350adbe1bc
generic

mptcp: pm: only set fullmesh for subflow endp - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8ac344cbd84fda75e05e1f445f7f8fb24dc175e1
generic

mptcp: pm: only set fullmesh for subflow endp - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/22b0734c9401a74ed4ebd9e8ef0da33e493852eb
generic

mptcp: pm: only set fullmesh for subflow endp - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1bb0d1348546ad059f55c93def34e67cb2a034a6

Vendor Advisories for CVE-2025-21706(1)

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

Patch Availability(10)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2028.29) @ noble2026-05-30ubuntu
ubuntulinux-tools-ibm-lts-24.04 (6.8.0-1033.33) @ noble2026-05-30ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1032.33) @ noble2026-05-30ubuntu
ubuntulinux-tools-aws (6.11.0-1014.15) @ oracular2026-05-30ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.11.0-26.26~24.04.1) @ noble2026-05-30ubuntu
ubuntulinux-virtual-6.8 (6.8.0-78.78) @ noble2026-05-30ubuntu
ubuntulinux-tools-oracle-64k (6.11.0-1016.17) @ oracular2026-05-30ubuntu
ubuntulinux-tools-raspi-6.8 (6.8.0-1035.39) @ noble2026-05-30ubuntu
ubuntulinux-tools-azure-nvidia-lts-24.04 (6.8.0-1022.23) @ noble2026-05-30ubuntu
linuxKernel @ 6.1.129—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

(9)

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 7× in last 7d / 42× 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 112 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. 2026-08-04 15:09 UTCEPSS rescore
  5. 2026-08-04 10:37 UTCEPSS rescore
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  7. 2026-08-02 02:25 UTCEPSS rescore
  8. 2026-08-01 04:15 UTCEPSS rescore
  9. 2026-07-30 16:27 UTCEPSS rescore
  10. 2026-07-30 01:29 UTCEPSS rescore
  11. 2026-07-28 15:35 UTCEPSS rescore
  12. 2026-07-27 14:12 UTCEPSS rescore
  13. 2026-07-26 14:53 UTCEPSS rescore
  14. 2026-07-25 14:17 UTCEPSS rescore
  15. 2026-07-24 14:17 UTCEPSS rescore
  16. 2026-07-24 13:41 UTCOSV refresh
  17. 2026-07-23 14:17 UTCEPSS rescore
  18. 2026-07-23 02:50 UTCEG score recompute
  19. 2026-07-22 14:07 UTCEPSS rescore
  20. 2026-07-22 14:07 UTCEPSS rescore
  21. 2026-07-21 15:24 UTCEPSS rescore
  22. 2026-07-20 17:07 UTCEPSS rescore
  23. 2026-07-19 14:30 UTCEPSS rescore
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  25. 2026-07-19 02:28 UTCEPSS rescore
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  1. 2026-07-19 02:28 UTCEPSS rescore
  2. 2026-07-18 10:03 UTCEPSS rescore
  3. 2026-07-16 17:02 UTCEPSS rescore
  4. 2026-07-15 16:57 UTCEPSS rescore
  5. 2026-07-15 16:57 UTCEPSS rescore
  6. 2026-07-15 01:59 UTCEPSS rescore
  7. 2026-07-14 13:19 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  8. 2026-07-14 13:11 UTCMITRE cvelistV5
  9. 2026-07-13 22:29 UTCEPSS rescore
  10. 2026-07-13 22:29 UTCEPSS rescore
  11. 2026-07-13 06:12 UTCEPSS rescore
  12. 2026-07-13 06:12 UTCEPSS rescore
  13. 2026-07-12 05:46 UTCEPSS rescore
  14. 2026-07-12 05:46 UTCEPSS rescore
  15. 2026-07-11 08:27 UTCEPSS rescore
  16. 2026-07-11 08:26 UTCEPSS rescore
  17. 2026-07-09 19:09 UTCEPSS rescore
  18. 2026-07-08 15:14 UTCEPSS rescore
  19. 2026-07-07 13:45 UTCEPSS rescore
  20. 2026-07-07 09:21 UTCOSV refresh
  21. 2026-07-06 16:26 UTCEPSS rescore
  22. 2026-07-06 02:22 UTCEPSS rescore
  23. 2026-07-06 02:22 UTCEPSS rescore
  24. 2026-07-05 02:30 UTCEPSS rescore
  25. 2026-07-04 06:30 UTCEPSS rescore
  26. 2026-07-01 15:06 UTCEPSS rescore
  27. 2026-06-30 23:21 UTCEPSS rescore
  28. 2026-06-30 23:21 UTCEPSS rescore
  29. 2026-06-29 14:06 UTCEPSS rescore
  30. 2026-06-28 14:07 UTCEPSS rescore
  31. 2026-06-28 14:07 UTCEPSS rescore
  32. 2026-06-28 04:55 UTCEPSS rescore
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  34. 2026-06-27 03:08 UTCEPSS rescore
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  36. 2026-06-25 13:49 UTCEPSS rescore
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  38. 2026-06-24 14:04 UTCEPSS rescore
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  40. 2026-06-23 21:32 UTCEPSS rescore
  41. 2026-06-23 21:32 UTCEPSS rescore
  42. 2026-06-22 14:25 UTCEPSS rescore
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  44. 2026-06-21 14:56 UTCEPSS rescore
  45. 2026-06-21 14:56 UTCEPSS rescore
  46. 2026-06-21 01:59 UTCEPSS rescore
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  48. 2026-06-19 19:25 UTCEPSS rescore
  49. 2026-06-19 19:25 UTCEPSS rescore
  50. 2026-06-18 20:13 UTCOSV refresh
  51. 2026-06-18 17:52 UTCEPSS rescore
  52. 2026-06-18 17:52 UTCEPSS rescore
  53. 2026-06-17 17:52 UTCEPSS rescore
  54. 2026-06-16 17:52 UTCEPSS rescore
  55. 2026-06-16 17:52 UTCEPSS rescore
  56. 2026-06-15 17:48 UTCEPSS rescore
  57. 2026-06-14 23:17 UTCEPSS rescore
  58. 2026-06-13 22:59 UTCEPSS rescore
  59. 2026-06-12 23:11 UTCEPSS rescore
  60. 2026-06-11 13:59 UTCEPSS rescore
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  63. 2026-06-08 14:16 UTCEPSS rescore
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  65. 2026-06-07 15:24 UTCEPSS rescore
  66. 2026-06-07 15:24 UTCEPSS rescore
  67. 2026-06-06 13:47 UTCEPSS rescore
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  73. 2026-06-04 13:11 UTCEPSS rescore
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  75. 2026-06-02 20:12 UTCEPSS rescore

Frequently asked(5)

What is CVE-2025-21706?
CVE-2025-21706 is a medium vulnerability published on February 27, 2025. In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: only set fullmesh for subflow endp With the in-kernel path-manager, it is possible to change the 'fullmesh' flag. The code in mptcppmnl_fullmesh() expects to change it only on 'subflow' endpoints, to recreate more or…
When was CVE-2025-21706 disclosed?
CVE-2025-21706 was first published in the National Vulnerability Database on February 27, 2025, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-21706 actively exploited?
CVE-2025-21706 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 89.3% of all scored CVEs.
What is the CVSS score of CVE-2025-21706?
CVE-2025-21706 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-21706?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21706, 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.

Dependency Blast Radius

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