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CVE.org (no NVD analysis yet)· CNA GitHub_M

CVE-2026-107837: RIOT: Out-of-Bounds Read in RIOT OS 6LoWPAN SFF Fragment Handling

HighCVSS 8.2 · v3.1—No exploit No fix recorded

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.37% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • No fixed version is recorded, but the references include a patch (commit or PR) link.

Low priority for now. See the fix and affected versions sections below.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. In 2026.07 and earlier, _receive() in sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c can route an undersized packet into SFF fragment handling after only a minimal payload check. The code then interprets the packet as a sixlowpan_frag_t or larger fragment header without verifying that the packet snip contains the required bytes. A remote attacker can send a malformed 6LoWPAN fragment that causes gnrc_sixlowpan_frag_recv() to read beyond the packet buffer, potentially disclosing memory and crashing the network stack. No fixed repository release is available as of this review.

Published
Oct 9, 2026
Updated
Oct 16, 2026
EPSS
0.3% · 32th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.2
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-107837

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • RIOT-OS RIOT

    • <= 2026.07affected

Same product

riot-os: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-27427RIOT OS Integer Overflow or Wraparound
    40Plan
  • CVE-2026-49868RIOT: DHCPv6 client _parse_reply() missing sub-option length check leads to size_t underflow and unbounded OOB heap read
    39Monitor
  • CVE-2026-27703RIOT has an Out-of-Bounds Write in nanoCoAP Handler
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-25139Feb 4, 2026 · RIOT Vulnerable to Multiple Out-of-Bounds Read When Processing Received 6LoWPAN SFR Fragments
    34Monitor
  • ← EarlierCVE-2026-107836Oct 9, 2026 · RIOT: nanoCoAP Block2 client slice handling underflows on inconsistent server-controlled block size
    28Monitor
  • Later →CVE-2026-107838Oct 9, 2026 · RIOT: nanocoap_fileserver ignores response initialization failure, leading to reachable assertion
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-498687 days apartRIOT: DHCPv6 client _parse_reply() missing sub-option length check leads to size_t underflow and unbounded OOB heap read
    39Monitor
  • CVE-2026-25139247 days apartRIOT Vulnerable to Multiple Out-of-Bounds Read When Processing Received 6LoWPAN SFR Fragments
    34Monitor
  • CVE-2026-1078360 days apartRIOT: nanoCoAP Block2 client slice handling underflows on inconsistent server-controlled block size
    28Monitor

Not on record for this CVE: researcher credit · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records