CVE-2026-126957: zephyrproject-rtos Zephyr · Out-of-bounds Read
Affects zephyrproject-rtos ZephyrSource CVE Database V5
Not known to be exploited · CVSS 5.3 Medium.
Data as of 12 Nov 2026, 02:48 UTC
Thin evidence
One scorer or none| CNA (zephyr) | CVSS 3.1 | 5.3 |
|---|---|---|
| CNA (zephyr) | CVSS 4.0 | 6.9 |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 12 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| zephyrproject-rtosZephyr | Affected
| Fixed in– |
GitHubZephyrpkg:github/ZephyrOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, consider disabling CONFIG_NET_IPV4_HDR_OPTIONS or CONFIG_NET_IPV4_IGMP if feasible to mitigate exposure. Monitor vendor channels for updates and apply patches promptly once released.
Description
CVE-2026-126957 is an integer underflow vulnerability in Zephyr's IPv4 option handling that allows a remote unauthenticated attacker to read up to 213 bytes of stack memory. The flaw occurs when processing ICMP Echo Requests with IPv4 Record Route or Timestamp options, leading to out-of-bounds reads and information leakage. Devices built with CONFIG_NET_IPV4_HDR_OPTIONS (selected by CONFIG_NET_IPV4_IGMP) and running Zephyr versions up to 4.4.0 are affected. The vulnerability does not cause crashes and can be repeatedly exploited to leak memory contents.