CVE-2026-48685

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory published 2026-05-26. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 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 has out-of-bounds memory access because it incorrectly parses BGP path attributes with the extended length flag set. In src/bgp_protocol.hpp, the parse_raw_bgp_attribute() function correctly identifies when extended_length_bit is set and sets length_of_length_field to 2, but then reads only a single byte for the attribute value length (attribute_value_length = value[2] at line 173). Per RFC 4271 Section 4.3, when the Extended Length bit is set, the Attribute Length field is two octets and the value should be read as a 16-bit big-endian integer from value[2] and value[3]. As a result, any attribute longer than 255 bytes has its length silently truncated to the low byte (e.g., 300 bytes = 0x012C is read as 0x2C = 44 bytes). The remaining 256 bytes are then misinterpreted as subsequent attributes, causing cascading parse failures and potential out-of-bounds memory access.

CVSS v3
6.5
EG Score
6.5(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
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

May 26, 2026

Last Modified

July 24, 2026

Advisory Details (3)

Auto-updated Jun 13, 2026
No patch confirmed yet.
generic

CVE-2026-48685: FastNetMon Reads One Byte of a Two-Byte BGP Attribute Length | Lorikeet Security

https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48685-bgp-extended-length
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-2026-48685(1)

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

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
fastnetmon1.2.4-2 ... 1.2.9-1 (14 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
fastnetmon1.2.8+git20250911-1, 1.2.8+git20250911-2, 1.2.8-11.2.9-0+deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
fastnetmon1.2.8+git20250911-1, 1.2.8+git20250911-2, 1.2.8-11.2.9-1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 32× 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 189 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-48685?
CVE-2026-48685 is a medium vulnerability published on May 26, 2026. FastNetMon Community Edition through 1.2.9 has out-of-bounds memory access because it incorrectly parses BGP path attributes with the extended length flag set. In src/bgpprotocol.hpp, the parserawbgpattribute() function correctly identifies when extendedlengthbit is set and sets lengthoflengthfield…
When was CVE-2026-48685 disclosed?
CVE-2026-48685 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-2026-48685 actively exploited?
CVE-2026-48685 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 77.9% of all scored CVEs.
What is the CVSS score of CVE-2026-48685?
CVE-2026-48685 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-48685?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48685, 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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