CVE catalog
CVE-2026-87121
lwIP TCP/IP Stack MQTT is vulnerable to an out-of-bounds write, which may allow an attacker to gain full code execution on the device.
- Severity
- Critical · CVSS 9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 0.78% · Oct 25, 2026
lwIP TCP/IP Stack MQTT is vulnerable to an out-of-bounds write, which may allow an attacker to gain full code execution on the device.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | lwip | sid | 2.2.1+dfsg1-9 | fixed |
| Debian | lwip | forky | 2.2.1+dfsg1-8 | fixed |
| Debian | lwip | trixie | 2.2.1+dfsg1-1+deb13u1 | vulnerable |
| Debian | lwip | bookworm | 2.1.3+dfsg1-2 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | lwip | source | sid | 2.2.1+dfsg1-8 | unimportant | Not reported | [1148822] |
| Debian | lwip | source | forky | 2.2.1+dfsg1-8 | unimportant | Not reported | [1148822] |
| Debian | lwip | source | trixie | (unfixed) | unimportant | Not reported | [1148822] |
| Debian | lwip | source | bookworm | (unfixed) | unimportant | Not reported | [1148822] |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [liblwip0]Affected
Source package: [lwip]
Details (2)
2.1.3+dfsg1-2· amd64 · bookwormAffected
nvd · lwip · debian · bookworm; nvd · lwip · debian · 12
2.1.3+dfsg1-2· arm64 · bookwormAffected
nvd · lwip · debian · bookworm; nvd · lwip · debian · 12
- [liblwip-dev]Affected
Source package: [lwip]
Details (2)
2.1.3+dfsg1-2· amd64 · bookwormAffected
nvd · lwip · debian · bookworm; nvd · lwip · debian · 12
2.1.3+dfsg1-2· arm64 · bookwormAffected
nvd · lwip · debian · bookworm; nvd · lwip · debian · 12
- [liblwip-doc]Affected
Source package: [lwip]
Details (2)
2.1.3+dfsg1-2· all · bookwormAffected
nvd · lwip · debian · bookworm; nvd · lwip · debian · 12
2.1.3+dfsg1-2· all · bookwormAffected
nvd · lwip · debian · bookworm; nvd · lwip · debian · 12
[Debian 13 (Trixie)]
- [liblwip0t64]Affected
Source package: [lwip]
Details (2)
2.2.1+dfsg1-1· amd64 · trixieAffected
nvd · lwip · debian · 13
2.2.1+dfsg1-1· arm64 · trixieAffected
nvd · lwip · debian · 13
- [liblwip-dev]Affected
Source package: [lwip]
Details (2)
2.2.1+dfsg1-1· amd64 · trixieAffected
nvd · lwip · debian · 13
2.2.1+dfsg1-1· arm64 · trixieAffected
nvd · lwip · debian · 13
- [liblwip-doc]Affected
Source package: [lwip]
Details (2)
2.2.1+dfsg1-1· all · trixieAffected
nvd · lwip · debian · 13
2.2.1+dfsg1-1· all · trixieAffected
nvd · lwip · debian · 13
Observed:
References
- [https://nvd.nist.gov/vuln/detail/CVE-2026-87121]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-87121]
- [https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-265-01.json]
- [https://security-tracker.debian.org/tracker/CVE-2026-87121]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-87121.json]
[CISA cybersecurity advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]