CVE-2026-47077
DoS via unbounded HTTP/3 buffering in hackney <4.0.1.
Is CVE-2026-47077 being exploited?
Not confirmed. CVE-2026-47077 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.70% probability of exploitation in the next 30 days.
How severe is CVE-2026-47077?
CVE-2026-47077 is rated High with a CVSS score of 8.2. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-47077?
Yes. A fix has been recorded for CVE-2026-47077. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-47077 affect?
CVE-2026-47077 affects hackney <4.0.1 (Erlang/Elixir HTTP client). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-47077?
Upgrade to hackney 4.0.1
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
OOM of BEAM process due to unbounded HTTP/3 response accumulation; possible app crash and service disruption.
Patch when possible
- affected>= 2.0.0 and < 4.0.1
- affected>= 0334af206d5099fdf510ed9eda18e34396f065ad and < 3d25f9fea26c90609de9d64366fedfe5065413bc
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.