RUSTSEC-2026-0258 GHSA-q83h-524g-xf6h

h2 unbounded empty DATA frames

Not rated yet crates.io

Severity: Not rated yet; No source has published a CVSS score yet
Exploit chance (EPSS): —; No score published
Known exploited: No; Not in CISA's catalog
Weakness: —; Not classified
Fix: 0.4.16; Upgrade h2 to this version or later

Description

The h2 crate, used internally by hyper, had a flaw that would accept and queue empty DATA frames without limit. If streams were not actively drained, this could lead to unbounded memory usage, or a panic if the length overflows.

Low severity.

Patched in v0.4.16.

Affected versions

crates.io

Package	Vulnerable	Fixed in
h2	`>= 0.0.0-0, < 0.4.16`	`0.4.16`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

h2 crates.io → `0.4.16`

cargo

cargo update -p h2 --precise 0.4.16

References

Advisories

rustsec.org/advisories/RUSTSEC-2026-0258.html

Packages

crates.io/crates/h2

Timeline

Aug 17, 2026 Published
Oct 12, 2026 Last updated by the source

Advisory	Severity	Why it's related
GHSA-q6cp-qfwq-4gcv h2 servers vulnerable to degradation of service with CONTINUATION Flood	Medium	Also affects h2
GHSA-8r5v-vm4m-4g25 Resource exhaustion vulnerability in h2 may lead to Denial of Service (DoS)	High	Also affects h2
GHSA-f8vr-r385-rh5r h2 vulnerable to denial of service	High	Also affects h2

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