CVE-2026-48691

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-26. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: NoneExposed: 0

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

FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attribute_length as 'sizeof(bgp_as_path_segment_element_t) + this->as_path_asns.size() * sizeof(uint32_t)' and stores it in a uint8_t field (line 600-605). Since uint8_t can only hold values 0-255, an AS_PATH containing more than 63 ASNs (2 + 64*4 = 258 > 255) causes silent truncation. The truncated length is used for buffer sizing, while the actual data written is the full untruncated amount, resulting in a heap buffer overflow. Similarly, the path_segment_length field at line 621 is also uint8_t, truncating with more than 255 ASNs.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
23%
KEV
Not listed

Published

May 26, 2026

Last Modified

July 24, 2026

Advisory Details (3)

Auto-updated Jul 24, 2026
No patch confirmed yet.
generic

CVE-2026-48691: A uint8_t Holds the BGP AS_PATH Length in FastNetMon | Lorikeet Security

https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48691-bgp-as-path-overflow
generic

fastnetmon/src/bgp_protocol.hpp at master · pavel-odintsov/fastnetmon · GitHub

https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.hpp
generic

GitHub - pavel-odintsov/fastnetmon: Very fast DDoS sensor with sFlow/Netflow/IPFIX/SPAN support · GitHub

https://github.com/pavel-odintsov/fastnetmon

Vendor Advisories for CVE-2026-48691(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 47× 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 192 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-48691?
CVE-2026-48691 is a critical vulnerability published on May 26, 2026. FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP ASPATH attribute encoder. In src/bgpprotocol.hpp, the IPv4UnicastAnnounce::getattributes() function computes attributelength as 'sizeof(bgpaspathsegmentelementt) + this->aspathasns.size() * sizeof(uint32t)' and…
When was CVE-2026-48691 disclosed?
CVE-2026-48691 was first published in the National Vulnerability Database on May 26, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-48691 actively exploited?
CVE-2026-48691 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 76.9% of all scored CVEs.
What is the CVSS score of CVE-2026-48691?
CVE-2026-48691 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-48691?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48691, 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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