CVE-2026-105659

HIGHCVSS 8.7/10EPSS 0.53%

Last modified

CVE-2026-105659 is a high-severity vulnerability rated 8.7/10 on the CVSS scale. Uncontrolled Resource Consumption vulnerability in mtrudel bandit allows an unauthenticated remote attacker to pin HTTP/2 stream processes indefinitely via a trickle of small WINDOW_UPDATE frames. A stream whose response outruns the connection or stream send window blocks until the peer grants more window, and each block carries a 15 second deadline. EPSS estimates a 0.53% chance of exploitation in the next 30 days.

Description

Uncontrolled Resource Consumption vulnerability in mtrudel bandit allows an unauthenticated remote attacker to pin HTTP/2 stream processes indefinitely via a trickle of small WINDOW_UPDATE frames. A stream whose response outruns the connection or stream send window blocks until the peer grants more window, and each block carries a 15 second deadline. Both deadlines restart whenever the peer makes partial progress. Bandit.HTTP2.Connection.finish_data/5 re-queues a partially advanced send in pending_sends with a fresh expires_at, so every WINDOW_UPDATE on stream 0, and every SETTINGS frame, resets the clock. Bandit.HTTP2.Stream.send_data/3 recurses on each stream WINDOW_UPDATE and re-arms a fresh after read_timeout. A peer that grants a few bytes every few seconds keeps the blocked stream process, its Plug state and any resource it holds mid-response alive for as long as it keeps dripping, and repeats this across streams and connections to exhaust server processes and memory. The two paths are independent. The stream-level block is reached on its own by widening the connection window with a large WINDOW_UPDATE on stream 0 and shrinking the per-stream window with a small SETTINGS_INITIAL_WINDOW_SIZE, so closing only the connection-level path leaves it exploitable. This issue affects bandit: from 1.4.0 before 1.13.0.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
mtrudelbandit>= 1.4.0, < *
mtrudelbandit>= fff06efe3be962b484bd4d3eb339372fda5a231f, < d88b21953c65061f21136ea76a89a4f95a2ac7a1

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-105659?
Uncontrolled Resource Consumption vulnerability in mtrudel bandit allows an unauthenticated remote attacker to pin HTTP/2 stream processes indefinitely via a trickle of small WINDOW_UPDATE frames. A stream whose response outruns the connection or stream send window blocks until the peer grants more window, and each block carries a 15 second deadline. Both deadlines restart whenever the peer makes partial progress. Bandit.HTTP2.Connection.finish_data/5 re-queues a partially advanced send in pending_sends with a fresh expires_at, so every WINDOW_UPDATE on stream 0, and every SETTINGS frame, resets the clock. Bandit.HTTP2.Stream.send_data/3 recurses on each stream WINDOW_UPDATE and re-arms a fresh after read_timeout. A peer that grants a few bytes every few seconds keeps the blocked stream process, its Plug state and any resource it holds mid-response alive for as long as it keeps dripping, and repeats this across streams and connections to exhaust server processes and memory. The two paths are independent. The stream-level block is reached on its own by widening the connection window with a large WINDOW_UPDATE on stream 0 and shrinking the per-stream window with a small SETTINGS_INITIAL_WINDOW_SIZE, so closing only the connection-level path leaves it exploitable. This issue affects bandit: from 1.4.0 before 1.13.0.
How severe is CVE-2026-105659?
CVE-2026-105659 has a CVSS score of 8.7/10 (HIGH severity). The EPSS model estimates a 0.53% probability of exploitation in the next 30 days.
How do I fix CVE-2026-105659?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST