CVE-2026-111497

criticalpriority · track · 10EPSS 0.005 · 41 %ileexploit · PoCDENLRUUS
grimoire priorityP1 · Urgent
Exploitable?
Public exploit
18 exploits · PoC
Likely / severe?
0.48% (41st) EPSS
CVSS 9.8 · critical
Is it mine?
18 products
Check your exposure
Who says so?
4 sources
fstec_bdu · osv · cert_bund · ncsc_nl

EPSS · scored 2026-10-23

A buffer overflow vulnerability in the Brotli decoder (c/dec/decode.c) in Google Brotli versions 1.0.3 through 1.2.0 on all platforms allows a remote unauthenticated attacker to corrupt adjacent decoder state memory, disclose sensitive memory contents, cause a denial of service, or potentially execute arbitrary code using a crafted Brotli-compressed stream. Users need to update any Brotli libraries or binaries between 1.0.3 through 1.2.0 to the latest available version: 1.0.10 or 1.1.1 or 1.2.1.

01

cvss

Technical severity, 0–10. One row per scoring source.

9.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.2–9.8

v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v4.09.2criticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · cve-coordination@google.com
v4.08.2highCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

exploits (18)

Public proof-of-concept and weaponised exploit code.

05

affected products (18)

Products and version ranges known to be affected.

06

advisories (6)

Vendor and ecosystem advisories describing this.

  • NCSC-2026-0453Kwetsbaarheid in Google Brotli-decoderNL2026-10-23csaf · ncsc_nlNL

    Google heeft een kwetsbaarheid verholpen in de Brotli-decompressiebibliotheek. Deze bibliotheek wordt onder meer gebruikt in Node.js.

  • WID-SEC-W-2026-4117Node.js: Mehrere SchwachstellenDeutsch2026-10-21csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Node.js ausnutzen, um einen Denial of Service Angriff durchzuführen, um Sicherheitsvorkehrungen zu umgehen und um beliebigen Programmcode auszuführen.

  • BIT-node-2026-1114972026-10-23vendor · osvUS

    A flaw in Node.js can cause Node.js Brotli decoder out-of-bounds write permits remote code execution. This vulnerability affects Node.js 22.x, 24.x, and 26.x.

  • BIT-node-min-2026-1114972026-10-23vendor · osvUS

    A flaw in Node.js can cause Node.js Brotli decoder out-of-bounds write permits remote code execution. This vulnerability affects Node.js 22.x, 24.x, and 26.x.

  • PYSEC-2026-4322Out-of-bounds write in the Brotli decoder ("Node2Shell") also affects the PyPI Brotli package2026-10-23vendor · osvUS

    CVE-2026-111497 ("Node2Shell") is an out-of-bounds write (CWE-787) in Google's Brotli decoder (c/dec/decode.c). DecodeBlockTypeAndLength() returns an ambiguous value for an invalid block switch, and the fast decode path discards it (CWE-252, unchecked return value), so a crafted Brotli stream makes the decoder continue on corrupted state and write past the ring buffer. Upstream rates it CVSS 4.0 9.2 and classifies the impact as potential remote code execution. The vulnerability is in Google's C library, not in Node.js specifically. The PyPI `Brotli` package is Google's CPython binding and compiles the same c/dec/decode.c that has the actual vulnerability. All `Brotli` releases up to and including 1.2.0 ship the vulnerable decoder; 1.2.1 contains the upstream fix (commit 0ed4268a) and differs from 1.2.0 only in that fix plus a version bump. The decoder is reached whenever untrusted Brotli data is decompressed. With `Brotli` installed, common HTTP clients decode Brotli responses automatically (urllib3/requests, httpx with the brotli extra, aiohttp) and services that accept `Content-Encoding: br` request bodies decode inbound data, so the flaw is reachable from attacker-controlled input.

  • PYSEC-2026-4323Out-of-bounds write in the brotlicffi decoder ("Node2Shell") also affects the PyPI Brotli package2026-10-23vendor · osvUS

    CVE-2026-111497 ("Node2Shell") is an out-of-bounds write (CWE-787) in Google's Brotli decoder (c/dec/decode.c). DecodeBlockTypeAndLength() returns an ambiguous value for an invalid block switch, and the fast decode path discards it (CWE-252, unchecked return value), so a crafted Brotli stream makes the decoder continue on corrupted state and write past the ring buffer. Upstream rates it CVSS 4.0 9.2 and classifies the impact as potential remote code execution. The vulnerability is in Google's C library, not in Node.js specifically. The PyPI `Brotli` package is Google's CPython binding and compiles the same c/dec/decode.c that has the original vulnerability. All `Brotli` releases up to and including 1.2.0 ship the vulnerable decoder; 1.2.1 contains the upstream fix (commit 0ed4268a) and differs from 1.2.0 only in that fix plus a version bump. The decoder is reached whenever untrusted Brotli data is decompressed. With `brotlicffi` installed, common HTTP clients decode Brotli responses automatically (urllib3/requests, httpx with the brotli extra, aiohttp) and services that accept `Content-Encoding: br` request bodies decode inbound data, so the flaw is reachable from attacker-controlled input.

07

also known as (5)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

published 2026-10-22modified 2026-10-23
09

references (4) nvd

External citations — patches, advisories, analysis.

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