CVE-2026-48685

MEDIUMNVD 6.56.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

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, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2026-31841 (ENISA EUVD) · GHSA-4h2g-xxvj-v3w5 (GitHub Security Advisories)Source: ENISA EUVD

6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
22nd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

May 26, 2026

Last Modified

July 24, 2026

Advisory Details (3)

Auto-updated Jun 13, 2026
Patch available.
Web page

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
Web page

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

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

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 rangeFix by version rangeDependents
fastnetmon1.2.4-2 ... 1.2.9-1 (14 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
fastnetmon1.2.8+git20250911-1, 1.2.8+git20250911-2, 1.2.8-1
  • every version up to 1.2.9-0+deb13u1: fixed in 1.2.9-0+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
fastnetmon1.2.8+git20250911-1, 1.2.8+git20250911-2, 1.2.8-1
  • every version up to 1.2.9-1: fixed in 1.2.9-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 39× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 240 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 140 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  2. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  4. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  5. 2026-10-30 13:55 UTCOSV refresh
  6. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  7. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  8. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  9. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  10. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  11. 2026-10-25 14:23 UTCEG score recompute
  12. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  13. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  14. 2026-10-22 23:04 UTCEG score recompute
  15. 2026-10-22 23:04 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  16. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  17. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  19. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  20. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  21. 2026-10-18 03:34 UTCEG score recompute
  22. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  23. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  24. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  25. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
Show 75 more
  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  3. 2026-10-12 16:00 UTCEG score recompute
  4. 2026-10-11 19:43 UTCEG score recompute
  5. 2026-10-11 16:58 UTCEG score recompute
  6. 2026-10-11 14:22 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  12. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  13. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  14. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  15. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  16. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  17. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  18. 2026-09-30 02:10 UTCOSV refresh
  19. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  20. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  21. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  22. 2026-09-26 00:27 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  23. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  24. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  25. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  26. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  27. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  28. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  29. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  30. 2026-09-11 03:23 UTCOSV refresh
  31. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  32. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  33. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  34. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  35. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  36. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  37. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  38. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  39. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  40. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  41. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  42. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  43. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  44. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  45. 2026-08-23 16:26 UTCEG score recompute
  46. 2026-08-23 16:26 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  47. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  48. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  49. 2026-08-21 21:32 UTCEG score recompute
  50. 2026-08-21 21:32 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  51. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  52. 2026-08-20 18:21 UTCEG score recompute
  53. 2026-08-20 18:21 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  54. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  55. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  56. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  57. 2026-08-17 09:36 UTCEG score recompute
  58. 2026-08-17 09:36 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  59. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  60. 2026-08-16 03:10 UTCEG score recompute
  61. 2026-08-16 03:10 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  62. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  63. 2026-08-15 02:07 UTCEG score recompute
  64. 2026-08-15 02:07 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  65. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  66. 2026-08-14 01:49 UTCEG score recompute
  67. 2026-08-14 01:48 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  68. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  69. 2026-08-13 01:30 UTCEG score recompute
  70. 2026-08-13 01:30 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  71. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  72. 2026-08-12 01:11 UTCEG score recompute
  73. 2026-08-12 01:11 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5
  74. 2026-08-11 00:52 UTCEG score recompute
  75. 2026-08-11 00:52 UTCGHSA enrichmentGHSA-4h2g-xxvj-v3w5 · GitHub CVSS 6.5

Frequently asked(5)

What is CVE-2026-48685?
CVE-2026-48685 is a medium-severity vulnerability; its CVE record was 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/bgp_protocol.hpp, the parse_raw_bgp_attribute() function correctly identifies when extended_length_bit is set and sets…
When was the CVE record for CVE-2026-48685 published?
The CVE record for CVE-2026-48685 was published on May 26, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 24, 2026; the record at its source may have been updated since.
Is CVE-2026-48685 actively exploited?
CVE-2026-48685 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (22nd percentile of EPSS-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?
A fix for CVE-2026-48685 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-48685 are linked in the Vendor Advisories panel on this page.

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