CVE-2026-111497: bun Memory Corruption

Description

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.

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CVSS v3.1 Score

9.8

CRITICAL

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

EPSS — Exploit Prediction

0.8264

Probability of exploitation

1.00%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

CISA Known Exploited Vulnerability

This vulnerability is actively exploited in the wild.

Added: Oct 27, 2026 Remediation due: Nov 10, 2026

Weakness Type (CWE)

CWE-252 CWE-252

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
google	brotli	1.0.3 — 1.0.10
google	brotli	1.1.0 — 1.1.1
google	brotli	1.2.0 — 1.2.1
nodejs	node.js	< 22.23.4
nodejs	node.js	23.0.0 — 24.22.1
nodejs	node.js	25.0.0 — 26.12.1
python-hyper	brotlicffi	< 1.2.1.0
microsoft	.net	8.0.0 — 8.0.33
microsoft	.net	9.0.0 — 9.0.22
microsoft	.net	10.0.0 — 10.0.14
microsoft	.net	All
microsoft	.net	All
microsoft	.net	All
microsoft	.net	All
microsoft	.net	All
microsoft	.net	All
microsoft	.net	All
microsoft	.net	All
microsoft	.net	All
debian	debian_linux	All
istio	istio	< 1.29.9
istio	istio	1.30.0 — 1.30.6
istio	istio	1.31.0 — 1.31.2
anthropic	bun	< 1.4.4
envoyproxy	envoy	< 1.37.8
envoyproxy	envoy	1.38.0 — 1.38.6
envoyproxy	envoy	1.39.0 — 1.39.3
tianocore	edk2	< 202608
google	woff2	All
duckdb	duckdb	< 2.0.0
clickhouse	clickhouse	< 26.10.2.103
apache	arrow	< 26.0.0
apache	arrow	All
mcmilk	7-zip-zstd	< 26.02-1.5.7-r2
7-zip	p7zip	< 16.02
andybalholm	brotli	< 1.2.7

References

Other References

https://github.com/andybalholm/brotli/releases/tag/v1.2.7 https://nodejs.org/en/blog/vulnerability/october-2026-security-releases#nodejs-brotli-decoder-out-of-bounds-write-permits-remote-code-execution-cve-2026-111497---high http://www.openwall.com/lists/oss-security/2026/10/23/25 http://www.openwall.com/lists/oss-security/2026/10/24/6 http://www.openwall.com/lists/oss-security/2026/10/26/12 http://www.openwall.com/lists/oss-security/2026/10/26/13 http://www.openwall.com/lists/oss-security/2026/10/26/16 https://broccoli2shell.com https://github.com/advisories/GHSA-9v8h-qqgm-4m35 https://github.com/dotnet/announcements/issues/494

Frequently Asked Questions

What is CVE-2026-111497? +

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. It has a CVSS v3.1 base score of 9.8 (CRITICAL). This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild.

How severe is CVE-2026-111497? +

CVE-2026-111497 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.8264, placing it in the 1th percentile for exploitation probability.

What products are affected by CVE-2026-111497? +

CVE-2026-111497 affects products from 7-zip, andybalholm, anthropic, apache, clickhouse, debian, duckdb, envoyproxy, google, istio, mcmilk, microsoft, nodejs, python-hyper, tianocore, specifically: .net, 7-zip-zstd, arrow, brotli, brotlicffi, bun, clickhouse, debian_linux, duckdb, edk2, envoy, istio, node.js, p7zip, woff2. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-111497? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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