CVE-2026-52939

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-06-24. 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

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion

rds_ib_xmit_atomic() always programs a masked atomic opcode (IB_WR_MASKED_ATOMIC_CMP_AND_SWP or IB_WR_MASKED_ATOMIC_FETCH_AND_ADD) for every RDS atomic cmsg. But the completion-side switch in rds_ib_send_unmap_op() only handles the non-masked opcodes, so a masked atomic completion falls through to default and returns rm == NULL while send->s_op is left set. rds_ib_send_cqe_handler() then dereferences the NULL rm via rm->m_final_op, oopsing in softirq context. An unprivileged AF_RDS sendmsg() of an atomic cmsg over an active RDS/IB connection triggers it; on hardware that natively accepts masked atomics (mlx4, mlx5) no extra setup is needed.

RDS/IB: rds_ib_send_unmap_op: unexpected opcode 0xd in WR! Oops: general protection fault [#1] SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000190-0x0000000000000197] RIP: rds_ib_send_cqe_handler+0x25c/0xb10 (net/rds/ib_send.c:282) Call Trace: rds_ib_send_cqe_handler (net/rds/ib_send.c:282) poll_scq (net/rds/ib_cm.c:274) rds_ib_tasklet_fn_send (net/rds/ib_cm.c:294) tasklet_action_common (kernel/softirq.c:943) handle_softirqs (kernel/softirq.c:573) run_ksoftirqd (kernel/softirq.c:479) Kernel panic - not syncing: Fatal exception in interrupt

Handle the masked atomic opcodes in the same case as the non-masked ones: they map to the same struct rds_message.atomic union member, so the existing container_of()/rds_ib_send_unmap_atomic() body is correct for them.

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
6%
KEV
Not listed

Published

June 24, 2026

Last Modified

July 8, 2026

Advisory Details (8)

Auto-updated Jul 8, 2026
No patch confirmed yet.
generic

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/dcf458120add64c96a6ef5cf719340453f6e6abf
generic

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a0148342badd8c9b2e46551766a27cb76c82e715
generic

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6e4615164d185a26badb2f376a2449f4d174a5f0
generic

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4fd34669558085bcb589aa2078a13b0ca79e360d
generic

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4dd262f875e87653df50b138de1390ab0628e6b7
generic

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/34080db3e70ddf94c38512ad2331e3c3afca6cc1
generic

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0f7baa82a24813cdad0b06a6f8f07e4824af5ed5
generic

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0f22412a2f4fbbe0251c132abee045d15a90e5b6

Vendor Advisories for CVE-2026-52939(1)

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

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)5.10.259-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.174-1~deb11u1 (20 versions)6.1.176-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)6.1.176-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)6.12.94-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (145 versions)7.0.13-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 5× 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 141 total refreshes for this CVE.

  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-10 09:35 UTCEPSS rescore
  3. 2026-09-08 22:01 UTCEPSS rescore
  4. 2026-09-07 16:01 UTCEPSS rescore
  5. 2026-09-06 13:47 UTCEPSS rescore
  6. 2026-09-04 05:06 UTCEPSS rescore
  7. 2026-09-02 14:12 UTCEPSS rescore
  8. 2026-09-01 13:54 UTCEPSS rescore
  9. 2026-09-01 04:40 UTCEPSS rescore
  10. 2026-08-30 20:21 UTCEG score recompute
  11. 2026-08-30 20:21 UTCGHSA enrichment
  12. 2026-08-30 19:17 UTCEPSS rescore
  13. 2026-08-30 01:22 UTCEPSS rescore
  14. 2026-08-28 21:41 UTCEPSS rescore
  15. 2026-08-28 04:52 UTCEG score recompute
  16. 2026-08-28 04:52 UTCGHSA enrichment
  17. 2026-08-27 14:25 UTCEPSS rescore
  18. 2026-08-26 14:46 UTCEPSS rescore
  19. 2026-08-25 13:49 UTCEPSS rescore
  20. 2026-08-24 22:02 UTCEG score recompute
  21. 2026-08-24 22:02 UTCGHSA enrichment
  22. 2026-08-23 14:40 UTCGHSA enrichment
  23. 2026-08-22 13:20 UTCEG score recompute
  24. 2026-08-22 13:20 UTCGHSA enrichment
  25. 2026-08-21 23:49 UTCEPSS rescore
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  1. 2026-08-21 09:16 UTCEG score recompute
  2. 2026-08-21 09:16 UTCGHSA enrichment
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 07:36 UTCEG score recompute
  5. 2026-08-20 07:36 UTCGHSA enrichment
  6. 2026-08-19 17:04 UTCEPSS rescore
  7. 2026-08-19 02:22 UTCEG score recompute
  8. 2026-08-19 02:22 UTCGHSA enrichment
  9. 2026-08-17 13:47 UTCEPSS rescore
  10. 2026-08-17 07:57 UTCGHSA enrichment
  11. 2026-08-16 06:38 UTCEG score recompute
  12. 2026-08-16 06:38 UTCGHSA enrichment
  13. 2026-08-16 02:14 UTCEPSS rescore
  14. 2026-08-15 05:19 UTCEG score recompute
  15. 2026-08-15 05:19 UTCGHSA enrichment
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-14 03:59 UTCEG score recompute
  18. 2026-08-14 03:59 UTCGHSA enrichment
  19. 2026-08-13 22:00 UTCEPSS rescore
  20. 2026-08-13 02:40 UTCEG score recompute
  21. 2026-08-13 02:40 UTCGHSA enrichment
  22. 2026-08-12 13:51 UTCEPSS rescore
  23. 2026-08-12 01:21 UTCEG score recompute
  24. 2026-08-12 01:21 UTCGHSA enrichment
  25. 2026-08-11 00:02 UTCEG score recompute
  26. 2026-08-11 00:02 UTCGHSA enrichment
  27. 2026-08-11 00:00 UTCEPSS rescore
  28. 2026-08-09 22:41 UTCGHSA enrichment
  29. 2026-08-08 21:22 UTCEG score recompute
  30. 2026-08-08 21:22 UTCGHSA enrichment
  31. 2026-08-08 16:37 UTCEPSS rescore
  32. 2026-08-07 20:02 UTCEG score recompute
  33. 2026-08-07 20:02 UTCGHSA enrichment
  34. 2026-08-06 18:42 UTCEG score recompute
  35. 2026-08-06 18:42 UTCGHSA enrichment
  36. 2026-08-06 13:47 UTCEPSS rescore
  37. 2026-08-05 19:17 UTCEPSS rescore
  38. 2026-08-05 17:23 UTCGHSA enrichment
  39. 2026-08-04 15:13 UTCEG score recompute
  40. 2026-08-04 15:13 UTCGHSA enrichment
  41. 2026-08-04 15:10 UTCEPSS rescore
  42. 2026-08-04 10:39 UTCEPSS rescore
  43. 2026-08-03 10:36 UTCEPSS rescore
  44. 2026-08-03 07:57 UTCGHSA enrichment
  45. 2026-08-02 06:30 UTCGHSA enrichment
  46. 2026-08-01 05:10 UTCEG score recompute
  47. 2026-08-01 05:10 UTCGHSA enrichment
  48. 2026-08-01 04:16 UTCEPSS rescore
  49. 2026-07-31 03:50 UTCEG score recompute
  50. 2026-07-31 03:50 UTCGHSA enrichment
  51. 2026-07-30 16:28 UTCEPSS rescore
  52. 2026-07-30 02:30 UTCEG score recompute
  53. 2026-07-30 02:30 UTCGHSA enrichment
  54. 2026-07-30 01:30 UTCEPSS rescore
  55. 2026-07-29 01:05 UTCEG score recompute
  56. 2026-07-29 01:05 UTCGHSA enrichment
  57. 2026-07-28 15:37 UTCEPSS rescore
  58. 2026-07-27 17:42 UTCGHSA enrichment
  59. 2026-07-26 15:44 UTCEG score recompute
  60. 2026-07-26 15:44 UTCGHSA enrichment
  61. 2026-07-25 14:18 UTCEPSS rescore
  62. 2026-07-24 14:18 UTCEPSS rescore
  63. 2026-07-23 03:19 UTCEG score recompute
  64. 2026-07-22 14:08 UTCEPSS rescore
  65. 2026-07-21 15:25 UTCEPSS rescore
  66. 2026-07-20 17:08 UTCEPSS rescore
  67. 2026-07-19 14:31 UTCEPSS rescore
  68. 2026-07-19 14:31 UTCEPSS rescore
  69. 2026-07-19 02:29 UTCEPSS rescore
  70. 2026-07-18 10:04 UTCEPSS rescore
  71. 2026-07-17 01:02 UTCGHSA enrichment
  72. 2026-07-16 17:03 UTCEPSS rescore
  73. 2026-07-15 23:38 UTCGHSA enrichment
  74. 2026-07-15 02:00 UTCEPSS rescore
  75. 2026-07-15 02:00 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-52939?
CVE-2026-52939 is a medium vulnerability published on June 24, 2026. In the Linux kernel, the following vulnerability has been resolved: net/rds: fix NULL deref in rdsibsendcqehandler() on masked atomic completion rdsibxmit_atomic() always programs a masked atomic opcode (IBWRMASKEDATOMICCMPANDSWP or IBWRMASKEDATOMICFETCHANDADD) for every RDS atomic cmsg. But the…
When was CVE-2026-52939 disclosed?
CVE-2026-52939 was first published in the National Vulnerability Database on June 24, 2026, with the most recent update on July 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52939 actively exploited?
CVE-2026-52939 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 94.2% of all scored CVEs.
What is the CVSS score of CVE-2026-52939?
CVE-2026-52939 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-52939?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52939, 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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