New MCP server — Bring vulnerability intelligence into your AI
Patrowl Intel
Back to feed

CVE-2026-24889

NVDCIRCLENISA

EUVD-2026-4848 · Published Jan 28, 2026

soroban-sdk has overflow in Bytes::slice, Vec::slice, GenRange::gen_range for u64

Impact

Arithmetic overflow can be triggered in the Bytes::slice, Vec::slice, and Prng::gen_range (for u64) methods in the soroban-sdk in versions prior to and including 25.0.1.

Contracts that pass user-controlled or computed range bounds to Bytes::slice, Vec::slice, or Prng::gen_range may silently operate on incorrect data ranges or generate random numbers from an unintended range, potentially resulting in corrupted contract state.

Note that the best practice when using the soroban-sdk and building Soroban contracts is to always enable overflow-checks = true. The stellar contract init tool that prepares the boiler plate for a Soroban contract, as well as all examples and docs, encourage the use of configuring overflow-checks = true on release profiles so that these arithmetic operations fail rather than silently wrap. Contracts are only impacted if they use overflow-checks = false either explicitly or implicitly. It is anticipated the majority of contracts could not be impacted because the best practice encouraged by tooling is to enable overflow-checks.

Detail

When compiled with overflow-checks = false (the default for release builds), the bare arithmetic in those functions silently wraps on boundary values like u32::MAX or u64::MAX. This causes the range passed to the host to differ from the caller's intent:

Bytes::slice:

  • Bytes::slice(0..=u32::MAX) — end u32::MAX + 1 wraps to 0, producing slice(0..0) returning empty instead of the full range.
  • Bytes::slice((Bound::Excluded(u32::MAX), Bound::Unbounded)) — start u32::MAX + 1 wraps to 0, producing slice(0..) instead of an empty/invalid range.

Vec::slice:

  • Vec::slice(0..=u32::MAX) — same as Bytes, end wraps to 0, returning empty.
  • Vec::slice((Bound::Excluded(u32::MAX), Bound::Unbounded)) — same as Bytes, start wraps to 0.

Prng::gen_range:

  • Prng::gen_range((Bound::Unbounded, Bound::Excluded(0))) — end 0 - 1 wraps to u64::MAX, producing range 0..=u64::MAX instead of an empty/invalid range.
  • Prng::gen_range((Bound::Excluded(u64::MAX), Bound::Unbounded)) — start u64::MAX + 1 wraps to 0, producing range 0..=u64::MAX instead of an empty/invalid range.

Note that some cases where the overflow was permitted and wrapped on the guest side are caught by the Soroban Env Host and cause a trap host side with error HostError: Error(Object, IndexBounds) object index out of bounds, because the wrapped values create invalid inputs:

  • Bytes::slice(u32::MAX..=u32::MAX) — both start u32::MAX + 1 and end u32::MAX + 1 wrap to 0, producing slice(0..0).
  • Vec::slice(u32::MAX..=u32::MAX) — same as Bytes, both wrap to 0.

Patches

The fix replaces bare arithmetic with checked_add / checked_sub, ensuring overflow traps regardless of the overflow-checks profile setting.

Workarounds

Contract workspaces can be configured with the following profile to enable overflow checks on the arithmetic operations. This is the best practice when developing Soroban contracts, and the default if using the contract boilerplate generated using stellar contract init:

[profile.release]
overflow-checks = true

Alternatively, contracts can validate range bounds before passing them to slice or gen_range to ensure the conversions cannot overflow:

  • Do not pass Bound::Excluded(u32::MAX) or Bound::Included(u32::MAX) to Bytes::slice or Vec::slice.
  • Do not pass Bound::Excluded(u64::MAX) as a start bound or Bound::Excluded(0) as an end bound to Prng::gen_range::<u64>.

References

Technologies

Stellar Rs-Soroban-SdkSoroban-Sdk Soroban-Sdk

Weaknesses

CWE-190

CVSS scores

  • v3.15.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

MITRE ATT&CK

Inferred

Where this vulnerability fits in an attack

Initial Access
T1190Exploit Public-Facing Application

References

Potentially impacted assets

See if this affects your attack surface

Latest trending attack

Criticaltoday

Google Brotli decoder - Remote Code Execution via compressed requests (Exploitation Check)

This control is the second step of the Patrowl response to CVE-2026-111497 (Node2Shell). It complements the first control of 22 October 2026, which focused on the Node.js runtime, and does not replace it. Why a second control CVE-2026-111497 is an out-of-bounds write in the Google Brotli decoder, the library that decompresses Brotli ("br") data. It was first published as a Node.js vulnerability, because Node.js bundles this decoder. Later publications showed that the flaw is in the library itself. Every product that embeds an affected version of the decoder is concerned, whatever its language or vendor. A public proof of concept demonstrates code execution. Any server that decompresses request bodies sent with "Content-Encoding: br" exposes the decoder to unauthenticated attackers. Known cases include Express 5 and NestJS 11 on Node.js, Koa and Fastify setups, Bun, Envoy and Istio with request decompression enabled, and any application or reverse proxy that decodes Brotli request bodies with an affected library. The flaw also works in the other direction. A malicious server can compromise an unpatched client that decodes a Brotli response, for example Node.js fetch(), Python clients (requests, httpx, aiohttp, Scrapy) with the Brotli or brotlicffi package, or libcurl builds with Brotli support. What this control checks Patrowl sends small, valid Brotli-compressed requests to each asset and observes whether the server decodes them. The check does not depend on the technology: it detects the behaviour, whatever the stack behind it. These requests are what any legitimate client could send. They never reach the vulnerable code path and cannot affect the availability of the service. How to read the result Potentially impacted means the asset decodes Brotli request bodies: the attack surface is exposed. It does not confirm that the asset is vulnerable. The version of the Brotli decoder in use is not visible from the outside. This check covers applications that parse request bodies on their root path. A Not impacted result does not rule out exposure on other routes, nor on the client side. Checking the versions on the servers remains the only exhaustive verification. Two situations are possible. When the decoding is done by your own application or reverse proxy, identify the component and update it. If an update is not possible right away, reject requests with "Content-Encoding: br" at the reverse proxy or WAF. When the asset is hosted on a managed platform or behind a CDN (for example Platform.sh, Upsun or Fastly), the decoding may be done by the provider's edge router, in front of your application. You cannot patch it yourself, but this router handles all the traffic of your site. Ask your provider to confirm that its edge components are patched against CVE-2026-111497. Assets hosted on a managed platform or behind a CDN carry the tag "paas: platform.sh" or "cdn: fastly" in the asset view: for these assets, the Brotli decoding is done by the provider's edge router, in front of your application, and only the provider can patch it. Affected and fixed versions Google Brotli 1.0.3 to 1.2.0 are affected, fixed in 1.0.10, 1.1.1 and 1.2.1. Fixed releases of the main products embedding it: Node.js 22.23.4, 24.22.1 and 26.12.1 (end-of-life lines 20.x and older and 25.x receive no fix), Bun 1.4.4, Envoy 1.37.8, 1.38.6, 1.39.3 and 1.40.0, Istio 1.29.9, 1.30.6 and 1.31.2, Python Brotli 1.2.1 and brotlicffi 1.2.1.0. Products that link against the system library depend on the Brotli package of the Linux distribution. Recommendations Update every component that embeds the Brotli decoder (only real fix). Start with the assets flagged by this control. Restart the processes after the update. Rebuild containers, single-executable applications and appliances that bundle an affected runtime or library. Reduce the exposure until the update is deployed. Reject requests with "Content-Encoding: br" at the reverse proxy, load balancer or WAF, case-insensitively and including lists such as "gzip, br". On Envoy and Istio, disable request decompression for Brotli. Contact your edge provider about the status of the pathing (Fastly / Plateform.sh) Review outbound calls. List the features that fetch content from servers you do not control, and patch the services that host them first.

News

Our latest news

Couldn’t load the latest news.

Take 15 minutes to discover our platform with our experts

Book your demo
PatrowlIntel platform screenshot