Brotli Flaw Reaches File-Processing Workflows, Expanding Exposure
Summary
Research on CVE-2026-111497 expands the affected-product list and shows Brotli can be reached through JPEG XL/FFmpeg file processing, with demonstrated memory corruption and instruction-pointer control. A reported Node.js exploitation attempt remains unconfirmed.
Key points
- Researchers demonstrated that a crafted JPEG XL image processed by affected FFmpeg deployments can reach the vulnerable Brotli decoder, causing memory corruption and instruction-pointer control.
- The affected-product list now includes Palo Alto PAN-OS, Prisma Cloud Application Security Transporter Client, PowerShell, Visual Studio, ClickHouse, DuckDB, Apache Arrow, MuPDF, and other projects bundling Brotli.
- Researchers reported a remote crash in ClickHouse from one malicious request, a .NET runtime crash, and an Apache Arrow infinite loop that causes denial of service.
- One threat-intelligence source reported an exploitation attempt against Node.js 24.22.0 on x86-64 systems; independent confirmation has not been published.
- Exposure depends on configuration in some products: PAN-OS requires both TLS decryption and Brotli inspection, while Envoy and Istio require Brotli decompression to be configured.
- The article recommends moving to vendor-fixed releases, rebuilding software with Brotli 1.2.1 or fixed libjxl, limiting untrusted JPEG XL processing until updates are available, and checking for bundled Brotli copies.
Article Details
- Vulnerability Types
- Memory corruption
- Code execution
- Denial of service
- Affected Versions
- Google Brotli C decoder 1.0.3 through 1.2.0
- Node.js 22.x below 22.23.4
- Node.js 24.x below 24.22.1
- Node.js 26.x below 26.12.1
- Node.js 25.x, 23.x, 20.x, and older release lines
- Bun before 1.4.4
- .NET 8.0 before 8.0.33, 9.0 before 9.0.22, and 10.0 before 10.0.14
- .NET 11 previews before 11.0.0-rc.3
- Python Brotli 1.0.3 through 1.2.0
- Python brotlicffi 1.0.3 through 1.2.0.2
- PowerShell 7.4, 7.5, and 7.6 before the October 25, 2026 updates
- Visual Studio 2019, 2022, and 2026 before the October 25, 2026 updates
- Envoy 1.39.2, 1.38.5, 1.37.7, and 1.36.11 when Brotli decompression is configured
- Istio before 1.29.9, 1.30.6, and 1.31.2 when Brotli decompression is enabled through an Envoy filter
- Prisma Cloud Application Security Transporter Client before 0.2.9
- Palo Alto PAN-OS 12.2 before 12.2.4-h1, 12.1.10 before 12.1.10-h3, 12.1.7 before 12.1.7-h11, 12.1.4 before 12.1.4-h13, 11.2.16 before 11.2.16-h1, 11.2.13 before 11.2.13-h4, and 11.2.4 before 11.2.4-h23, when TLS/SSL decryption and Brotli inspection are both enabled
- Red Hat Enterprise Linux 9 brotli before 1.0.9-10.el9_8.1
- ClickHouse 26.10.2.103 and the 26.9, 26.8, and 26.3 LTS lines
- Apache Arrow bundled builds using Brotli 1.0.9
- DuckDB (fix in progress; affected version not specified)
- MuPDF 1.27.x
- NanaZip 7.0.1873.0
- libjxl v0.12.0
- GraalJS 25.4.4.1.1
- Microsoft v8-jsi using Brotli 1.2.0
- 7-Zip-zstd using Brotli 1.2.0
- p7zip using Brotli 1.0.9
- EDK II using Brotli 1.2.0
- woff2 Makefile builds using Brotli 1.0.3
- Exploitation Status
- reported
- Exploit Availability
- public_poc
- Patch Status
- partial
- Workarounds
- Until updates are available, limit processing of untrusted JPEG XL images.
- Rebuild affected software against Brotli 1.2.1 or a libjxl build containing the fix.
- Rebuild or redeploy applications that bundle their own Brotli decoder; updating operating-system Brotli packages alone may not remediate them.
MITRE ATT&CK
T1190 · Exploit Public-Facing ApplicationThe article describes exploitation of vulnerable Node.js deployments through Brotli-compressed HTTP traffic and request bodies.T1499 · Endpoint Denial of ServiceA malicious request reportedly caused a remote crash in ClickHouse, and vulnerable processing caused crashes and an infinite-loop denial of service in other products.
CVE
Vendors
GoogleNew research shows the vulnerable Google Brotli decoder may be reachable through file-processing workflows, not just web traffic.MicrosoftMicrosoft v8-jsi (Brotli 1.2.0)Palo Alto Networkssince the disclosure of CVE-2026-111497 has identified additional affected products, including Palo Alto PAN-OS, Prisma Cloud Application Security Transporter Client, DuckDB, Apache Arrow, ClickHouse, MuPDF,Red HatThe Red Hat Enterprise Linux 9 Brotli package
Products
.NETEarly reporting focused primarily on software ecosystems known to bundle the decoder, including Node.js, .NET, Python, Envoy, Istio, and Bun.7-Zip-zstd7-Zip-zstd (Brotli 1.2.0)Apache Arrowproducts, including Palo Alto PAN-OS, Prisma Cloud Application Security Transporter Client, DuckDB, Apache Arrow, ClickHouse, MuPDF, and several other projects that bundle vulnerable Brotli code.BrotliClient, DuckDB, Apache Arrow, ClickHouse, MuPDF, and several other projects that bundle vulnerable Brotli code.ClickHouseincluding Palo Alto PAN-OS, Prisma Cloud Application Security Transporter Client, DuckDB, Apache Arrow, ClickHouse, MuPDF, and several other projects that bundle vulnerable Brotli code.DuckDBaffected products, including Palo Alto PAN-OS, Prisma Cloud Application Security Transporter Client, DuckDB, Apache Arrow, ClickHouse, MuPDF, and several other projects that bundle vulnerable Brotli code.EDK IIEDK II (Brotli 1.2.0)EnvoyEarly reporting focused primarily on software ecosystems known to bundle the decoder, including Node.js, .NET, Python, Envoy, Istio, and Bun.FFmpegJPEG XL and FFmpegGraalJSInvestigations also identified vulnerable bundled Brotli implementations in projects including ClickHouse, DuckDB, Apache Arrow, MuPDF, NanaZip, GraalJS, and libjxl.IstioEarly reporting focused primarily on software ecosystems known to bundle the decoder, including Node.js, .NET, Python, Envoy, Istio, and Bun.JPEG XLJPEG XL and FFmpeglibjxlInvestigations also identified vulnerable bundled Brotli implementations in projects including ClickHouse, DuckDB, Apache Arrow, MuPDF, NanaZip, GraalJS, and libjxl.Microsoft v8-jsiMicrosoft v8-jsi (Brotli 1.2.0)MuPDFPalo Alto PAN-OS, Prisma Cloud Application Security Transporter Client, DuckDB, Apache Arrow, ClickHouse, MuPDF, and several other projects that bundle vulnerable Brotli code.NanaZipInvestigations also identified vulnerable bundled Brotli implementations in projects including ClickHouse, DuckDB, Apache Arrow, MuPDF, NanaZip, GraalJS, and libjxl.Node.jsEarly reporting focused primarily on software ecosystems known to bundle the decoder, including Node.js, .NET, Python, Envoy, Istio, and Bun.p7zipp7zip (Brotli 1.0.9)Palo Alto PAN-OSsince the disclosure of CVE-2026-111497 has identified additional affected products, including Palo Alto PAN-OS, Prisma Cloud Application Security Transporter Client, DuckDB, Apache Arrow, ClickHouse, MuPDF, andPowerShellPowerShell 7.4, 7.5, and 7.6Prisma Cloud Application Security Transporter Clienthas identified additional affected products, including Palo Alto PAN-OS, Prisma Cloud Application Security Transporter Client, DuckDB, Apache Arrow, ClickHouse, MuPDF, and several other projects that bundleRed Hat Enterprise Linux 9The Red Hat Enterprise Linux 9 Brotli packageVisual StudioVisual Studio 2019, 2022, and 2026woff2woff2 Makefile builds (Brotli 1.0.3)