CVE-2026-45886

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-05-27. 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

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:

bpf: Fix bpf_xdp_store_bytes proto for read-only arg

While making some maps in Cilium read-only from the BPF side, we noticed that the bpf_xdp_store_bytes proto is incorrect. In particular, the verifier was throwing the following error:

; ret = ctx_store_bytes(ctx, l3_off + offsetof(struct iphdr, saddr), &nat->address, 4, 0); 635: (79) r1 = *(u64 *)(r10 -144) ; R1=ctx() R10=fp0 fp-144=ctx() 636: (b4) w2 = 26 ; R2=26 637: (b4) w4 = 4 ; R4=4 638: (b4) w5 = 0 ; R5=0 639: (85) call bpf_xdp_store_bytes#190 write into map forbidden, value_size=6 off=0 size=4

nat comes from a BPF_F_RDONLY_PROG map, so R3 is a PTR_TO_MAP_VALUE. The verifier checks the helper's memory access to R3 in check_mem_size_reg, as it reaches ARG_CONST_SIZE argument. The third argument has expected type ARG_PTR_TO_UNINIT_MEM, which includes the MEM_WRITE flag. The verifier thus checks for a BPF_WRITE access on R3. Given R3 points to a read-only map, the check fails.

Conversely, ARG_PTR_TO_UNINIT_MEM can also lead to the helper reading from uninitialized memory.

This patch simply fixes the expected argument type to match that of bpf_skb_store_bytes.

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

May 27, 2026

Last Modified

June 25, 2026

Advisory Details (6)

Auto-updated Jun 25, 2026
No patch confirmed yet.
generic

bpf: Fix bpf_xdp_store_bytes proto for read-only arg - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e
generic

bpf: Fix bpf_xdp_store_bytes proto for read-only arg - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ddc34a1b85505c919026ddc82fafdada9a160b15
generic

bpf: Fix bpf_xdp_store_bytes proto for read-only arg - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d7b87adeb0eb539b9b824b101bb14fb01e41240b
generic

bpf: Fix bpf_xdp_store_bytes proto for read-only arg - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6557f1565d779851c4db9c488c49c05a47a6e72f
generic

bpf: Fix bpf_xdp_store_bytes proto for read-only arg - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52
generic

bpf: Fix bpf_xdp_store_bytes proto for read-only arg - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0db169a91381a473b7974021d1c02f8da72c5775

Vendor Advisories for CVE-2026-45886(1)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 6.1.165—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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 37× 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.

  1. 2026-07-27 14:13 UTCEPSS rescore
  2. 2026-07-27 12:21 UTCEG score recompute
  3. 2026-07-27 12:21 UTCGHSA enrichment
  4. 2026-07-26 14:54 UTCEPSS rescore
  5. 2026-07-26 14:54 UTCEPSS rescore
  6. 2026-07-26 06:12 UTCOSV refresh
  7. 2026-07-25 14:18 UTCEPSS rescore
  8. 2026-07-24 14:17 UTCEPSS rescore
  9. 2026-07-23 14:18 UTCEPSS rescore
  10. 2026-07-23 03:16 UTCEG score recompute
  11. 2026-07-22 14:08 UTCEPSS rescore
  12. 2026-07-21 15:24 UTCEPSS rescore
  13. 2026-07-20 17:08 UTCEPSS rescore
  14. 2026-07-19 14:31 UTCEPSS rescore
  15. 2026-07-19 02:29 UTCEPSS rescore
  16. 2026-07-18 10:04 UTCEPSS rescore
  17. 2026-07-16 17:03 UTCEPSS rescore
  18. 2026-07-15 16:57 UTCEPSS rescore
  19. 2026-07-15 02:00 UTCEPSS rescore
  20. 2026-07-13 22:30 UTCEPSS rescore
  21. 2026-07-13 06:13 UTCEPSS rescore
  22. 2026-07-12 05:46 UTCEPSS rescore
  23. 2026-07-11 08:27 UTCEPSS rescore
  24. 2026-07-09 19:10 UTCEPSS rescore
  25. 2026-07-09 00:26 UTCGHSA enrichment
Show 73 more
  1. 2026-07-08 15:16 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-05 02:30 UTCEPSS rescore
  4. 2026-07-04 06:31 UTCEPSS rescore
  5. 2026-07-01 15:07 UTCEPSS rescore
  6. 2026-07-01 11:37 UTCGHSA enrichment
  7. 2026-06-30 23:22 UTCEPSS rescore
  8. 2026-06-29 22:16 UTCGHSA enrichment
  9. 2026-06-29 14:06 UTCEPSS rescore
  10. 2026-06-29 14:06 UTCEPSS rescore
  11. 2026-06-28 21:23 UTCGHSA enrichment
  12. 2026-06-28 14:07 UTCEPSS rescore
  13. 2026-06-28 04:56 UTCEPSS rescore
  14. 2026-06-28 04:56 UTCEPSS rescore
  15. 2026-06-27 19:19 UTCEG score recompute▲ 5.50
  16. 2026-06-27 19:19 UTCGHSA enrichment
  17. 2026-06-27 03:08 UTCEPSS rescore
  18. 2026-06-25 21:50 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  19. 2026-06-25 13:49 UTCEPSS rescore
  20. 2026-06-25 01:48 UTCGHSA enrichment
  21. 2026-06-24 14:05 UTCEPSS rescore
  22. 2026-06-23 21:33 UTCEPSS rescore
  23. 2026-06-23 21:33 UTCEPSS rescore
  24. 2026-06-22 14:25 UTCEPSS rescore
  25. 2026-06-22 14:25 UTCEPSS rescore
  26. 2026-06-21 14:56 UTCEPSS rescore
  27. 2026-06-21 14:56 UTCEPSS rescore
  28. 2026-06-21 01:59 UTCEPSS rescore
  29. 2026-06-21 01:59 UTCEPSS rescore
  30. 2026-06-19 19:26 UTCEPSS rescore
  31. 2026-06-19 19:26 UTCEPSS rescore
  32. 2026-06-18 17:52 UTCEPSS rescore
  33. 2026-06-18 17:52 UTCEPSS rescore
  34. 2026-06-17 17:53 UTCEPSS rescore
  35. 2026-06-17 10:49 UTCGHSA enrichment
  36. 2026-06-16 17:52 UTCEPSS rescore
  37. 2026-06-15 17:49 UTCEPSS rescore
  38. 2026-06-14 17:16 UTCGHSA enrichment
  39. 2026-06-13 23:00 UTCEPSS rescore
  40. 2026-06-12 23:12 UTCEPSS rescore
  41. 2026-06-12 23:12 UTCEPSS rescore
  42. 2026-06-11 23:45 UTCGHSA enrichment
  43. 2026-06-11 14:00 UTCEPSS rescore
  44. 2026-06-10 22:18 UTCEPSS rescore
  45. 2026-06-10 13:22 UTCEPSS rescore
  46. 2026-06-10 13:22 UTCEPSS rescore
  47. 2026-06-09 06:15 UTCGHSA enrichment
  48. 2026-06-08 14:17 UTCEPSS rescore
  49. 2026-06-08 14:17 UTCEPSS rescore
  50. 2026-06-07 15:25 UTCEPSS rescore
  51. 2026-06-07 15:25 UTCEPSS rescore
  52. 2026-06-06 13:47 UTCEPSS rescore
  53. 2026-06-06 13:47 UTCEPSS rescore
  54. 2026-06-06 12:44 UTCGHSA enrichment
  55. 2026-06-05 22:47 UTCEPSS rescore
  56. 2026-06-05 06:10 UTCEPSS rescore
  57. 2026-06-05 06:10 UTCEPSS rescore
  58. 2026-06-04 13:12 UTCEPSS rescore
  59. 2026-06-04 13:12 UTCEPSS rescore
  60. 2026-06-03 19:13 UTCGHSA enrichment
  61. 2026-06-02 20:13 UTCEPSS rescore
  62. 2026-06-01 13:52 UTCEPSS rescore
  63. 2026-06-01 13:52 UTCEPSS rescore
  64. 2026-06-01 01:42 UTCGHSA enrichment
  65. 2026-05-31 22:30 UTCEPSS rescore
  66. 2026-05-31 22:30 UTCEPSS rescore
  67. 2026-05-31 00:16 UTCEPSS rescore
  68. 2026-05-31 00:16 UTCEPSS rescore
  69. 2026-05-29 13:44 UTCEPSS rescore
  70. 2026-05-29 13:44 UTCEPSS rescore
  71. 2026-05-28 13:44 UTCEPSS rescore
  72. 2026-05-28 13:44 UTCEPSS rescore
  73. 2026-05-27 14:18 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-45886?
CVE-2026-45886 is a medium vulnerability published on May 27, 2026. In the Linux kernel, the following vulnerability has been resolved: bpf: Fix bpfxdpstore_bytes proto for read-only arg While making some maps in Cilium read-only from the BPF side, we noticed that the bpfxdpstore_bytes proto is incorrect. In particular, the verifier was throwing the following…
When was CVE-2026-45886 disclosed?
CVE-2026-45886 was first published in the National Vulnerability Database on May 27, 2026, with the most recent update on June 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45886 actively exploited?
CVE-2026-45886 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 94.4% of all scored CVEs.
What is the CVSS score of CVE-2026-45886?
CVE-2026-45886 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-45886?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45886, 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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