CVE-2026-13479

MEDIUMNVD 4.34.3
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 4.3 under NVD CVSS v3. EPSS exploit probability: 0.2% (13th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
4.3EG
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: 0.2%CVSS: 4.3Exploit: None knownExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

The LoRaWAN application-layer clock-synchronization service parses downlinks in clock_sync_package_callback() (subsys/lorawan/services/clock_sync.c). Its command loop only guarantees that the one-byte command id is in bounds; for the CLOCK_SYNC_CMD_APP_TIME (AppTimeAns) command the handler then reads a 4-byte time correction via sys_get_le32() plus a 1-byte token without checking that 5 bytes remain in the receive buffer (len - rx_pos). A short or crafted AppTimeAns therefore reads up to 5 bytes past the end of the decrypted payload.

The payload (rx_buf/len) is the decrypted application frame delivered to the registered downlink callback (mcps_indication->Buffer/BufferSize). Reaching the handler requires a frame on the clock-sync port that passes LoRaWAN's MAC integrity check and FRMPayload decryption, so the practical attacker is a malicious or compromised network/application server (the designated sender of AppTimeAns) or a party holding the session keys, rather than an arbitrary radio listener.

The over-read is bounded: the backing store is a fixed 255-byte static buffer, so the few stray bytes do not fault, and the read values (time_correction, token) are used only internally and never transmitted, so there is no disclosure to the attacker and no crash. The sole effect is that a stale token matching ctx.req_token can apply a garbage time_correction to the device's own clock offset (ctx.time_offset), a minor integrity impact confined to the victim's time estimate. The fix adds an explicit length check that drops a too-short AppTimeAns. Note the sibling one-byte reads in the periodicity and force-resync handlers remain unguarded with the same negligible impact.

CVSS v3
4.3
EG Score
4.3MEDIUMmedium confidence
EG Risk
19
EG Risk 19/100

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 (value × EchelonGraph’s weight)
Severity43% × 45%
The EG Score, 4.3 of 10.
Exploitation0.2% × 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 referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.
EPSS PROB
0.2%
EPSS %ILE
13th
KEV
Not listed

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

A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

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.

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

August 26, 2026

Last Modified

August 31, 2026

Advisory Details (2)

Auto-updated Aug 31, 2026
Fix referenced — no release confirmed yet. Sources: github, github_commit.
GitHub advisoryMentions a patch (unverified)

Out-of-bounds read in LoRaWAN clock-sync AppTimeAns downlink handler · Advisory · zephyrproject-rtos/zephyr · GitHub

https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2m6g-p3vx-p2fh
GitHub commit

commit 3d578067652b (zephyrproject-rtos/zephyr)

Fix landed in zephyrproject-rtos/zephyr commit 3d578067652b — awaiting tagged release

https://github.com/zephyrproject-rtos/zephyr/commit/3d578067652b12993bca13fb8e07dc45d062d4a5

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 48× 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.

  1. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  2. 2026-10-12 16:35 UTCEG score recompute
  3. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  4. 2026-10-11 20:11 UTCEG score recompute
  5. 2026-10-11 18:23 UTCEG score recompute
  6. 2026-10-11 14:57 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  8. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  9. 2026-10-10 06:34 UTCEG score recompute
  10. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  11. 2026-10-09 03:27 UTCEG score recompute
  12. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  13. 2026-10-08 01:56 UTCEG score recompute
  14. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  15. 2026-10-07 01:08 UTCEG score recompute
  16. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  17. 2026-10-06 01:44 UTCEG score recompute
  18. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  19. 2026-10-05 02:34 UTCEG score recompute
  20. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  21. 2026-10-04 03:50 UTCEG score recompute
  22. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  23. 2026-10-03 05:06 UTCEG score recompute
  24. 2026-10-02 06:22 UTCEG score recompute
  25. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.2% · 13th percentile
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  1. 2026-10-01 05:33 UTCEG score recompute
  2. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  3. 2026-09-30 06:08 UTCEG score recompute
  4. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  5. 2026-09-28 21:21 UTCEG score recompute
  6. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  7. 2026-09-27 19:53 UTCEG score recompute
  8. 2026-09-26 21:09 UTCEG score recompute
  9. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  10. 2026-09-25 11:45 UTCEG score recompute
  11. 2026-09-24 12:13 UTCEG score recompute
  12. 2026-09-23 13:47 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  13. 2026-09-23 13:28 UTCEG score recompute
  14. 2026-09-22 14:44 UTCEG score recompute
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  16. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  17. 2026-09-19 18:27 UTCEG score recompute
  18. 2026-09-18 19:43 UTCEG score recompute
  19. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  20. 2026-09-17 20:58 UTCEG score recompute
  21. 2026-09-16 19:08 UTCEG score recompute
  22. 2026-09-16 05:14 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  23. 2026-09-15 17:38 UTCEG score recompute
  24. 2026-09-13 19:01 UTCEG score recompute
  25. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  26. 2026-09-12 20:17 UTCEG score recompute
  27. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  28. 2026-09-11 21:33 UTCEG score recompute
  29. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  30. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  31. 2026-09-10 22:49 UTCEG score recompute
  32. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  33. 2026-09-09 00:51 UTCEG score recompute
  34. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  35. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  36. 2026-09-06 16:13 UTCEG score recompute
  37. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  38. 2026-09-05 17:29 UTCEG score recompute
  39. 2026-09-04 18:45 UTCEG score recompute
  40. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  41. 2026-09-02 21:07 UTCEG score recompute
  42. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  43. 2026-09-01 22:23 UTCEG score recompute
  44. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  45. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  46. 2026-08-31 23:39 UTCEG score recompute▲ 1.20
  47. 2026-08-31 23:38 UTCNVD updateCVSS v3 → 4.3 · severity → MEDIUM
  48. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  49. 2026-08-30 01:21 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  50. 2026-08-29 19:39 UTCEG score recompute
  51. 2026-08-28 21:40 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  52. 2026-08-27 14:24 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  53. 2026-08-26 16:21 UTCEG score recompute
  54. 2026-08-26 15:49 UTCEG score recompute
  55. 2026-08-26 14:23 UTCEG score recomputeFirst assessed: 3.1 LOW
  56. 2026-08-26 14:22 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-13479?
CVE-2026-13479 is a medium-severity vulnerability; its CVE record was published on August 26, 2026. The LoRaWAN application-layer clock-synchronization service parses downlinks in clocksyncpackagecallback() (subsys/lorawan/services/clocksync.c). Its command loop only guarantees that the one-byte command id is in bounds; for the CLOCKSYNCCMDAPPTIME (AppTimeAns) command the handler then reads a…
When was the CVE record for CVE-2026-13479 published?
The CVE record for CVE-2026-13479 was published on August 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 August 31, 2026; the record at its source may have been updated since.
Is CVE-2026-13479 actively exploited?
CVE-2026-13479 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (13th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-13479?
CVE-2026-13479 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-13479?
A fix for CVE-2026-13479 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

Dependency Blast Radius

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