CVE-2026-49868

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (31st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source

Also known asEUVD-2026-102947 (ENISA EUVD)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, _parse_reply() in sys/net/application_layer/dhcpv6/client.c omits minimum-length validation before passing IA_PD and IA_NA option bodies to sub-option parsers. A malicious or compromised DHCPv6 server can send a REPLY with an option length smaller than the required structure while MODULE_DHCPV6_CLIENT_IA_PD is enabled, causing _parse_ia_pd_option to read past the option body, size_t underflow, and unbounded out-of-bounds heap reads that can crash the device and may expose or corrupt memory. This issue is fixed in version 2026.07.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
44
EG Risk 44/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 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 low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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
0.4%
EPSS %ILE
31st
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). 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 low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 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 low or medium mission impact; Track* at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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)14 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 total (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

October 16, 2026

Last Modified

October 21, 2026

Advisory Details (4)

Auto-updated Oct 30, 2026
Patch available. Sources: github_pr, github_release, github, github_commit.
GitHub advisoryMentions a patch (unverified)

DHCPv6 client _parse_reply() missing sub-option length check leads to size_t underflow and unbounded OOB heap read · Advisory · RIOT-OS/RIOT · GitHub

https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-p3fx-9qcg-jmcf
GitHub release Patch Available

Release-2026.07

Patch available: RIOT-OS/RIOT 2026.07

https://github.com/RIOT-OS/RIOT/releases/tag/2026.07
GitHub pull request

sys/net/dhcpv6: guard against malicious packet length

Fix merged in RIOT-OS/RIOT PR #22322 on 2026-05-27 — awaiting tagged release

https://github.com/RIOT-OS/RIOT/pull/22322
GitHub commit

commit c9830dc5f2a9 (RIOT-OS/RIOT)

Fix landed in RIOT-OS/RIOT commit c9830dc5f2a9 — awaiting tagged release

https://github.com/RIOT-OS/RIOT/commit/c9830dc5f2a9bf97418de4fc7d7167d00a45df17

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 40× 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. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  2. 2026-11-02 14:29 UTCEG score recompute
  3. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  4. 2026-11-01 13:43 UTCEG score recompute
  5. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  6. 2026-10-31 12:57 UTCEG score recompute
  7. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  8. 2026-10-30 12:12 UTCEG score recompute
  9. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  10. 2026-10-29 11:27 UTCEG score recompute
  11. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  12. 2026-10-28 10:42 UTCEG score recompute
  13. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  14. 2026-10-27 09:06 UTCEG score recompute
  15. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  16. 2026-10-26 07:19 UTCEG score recompute
  17. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  18. 2026-10-25 14:22 UTCEG score recompute
  19. 2026-10-25 06:34 UTCEG score recompute
  20. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  21. 2026-10-24 05:48 UTCEG score recompute
  22. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  23. 2026-10-23 05:00 UTCEG score recompute
  24. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  25. 2026-10-22 04:14 UTCEG score recompute
Show 15 more
  1. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  2. 2026-10-21 03:27 UTCEG score recompute
  3. 2026-10-21 02:33 UTCEG score recompute
  4. 2026-10-20 23:41 UTCEG score recompute
  5. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  6. 2026-10-19 22:52 UTCEG score recompute
  7. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  8. 2026-10-18 22:06 UTCEG score recompute
  9. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  10. 2026-10-18 03:33 UTCEG score recompute
  11. 2026-10-17 20:54 UTCEG score recompute
  12. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  13. 2026-10-16 17:28 UTCEG score recompute
  14. 2026-10-16 16:59 UTCEG score recomputeFirst assessed: 9.8 CRITICAL
  15. 2026-10-16 16:57 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-49868?
CVE-2026-49868 is a critical-severity vulnerability; its CVE record was published on October 16, 2026. RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, _parse_reply() in sys/net/application_layer/dhcpv6/client.c omits minimum-length validation before passing IA_PD and IA_NA option bodies to sub-option…
When was the CVE record for CVE-2026-49868 published?
The CVE record for CVE-2026-49868 was published on October 16, 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 October 21, 2026; the record at its source may have been updated since.
Is CVE-2026-49868 actively exploited?
CVE-2026-49868 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (31st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-49868?
CVE-2026-49868 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-49868?
A fix for CVE-2026-49868 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-49868

Explore →

Is Your Infrastructure Affected by CVE-2026-49868?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs