CVE-2026-43973
Unbounded HTTP buffering in gun_http leads to memory exhaustion.
Is CVE-2026-43973 being exploited?
Not confirmed. CVE-2026-43973 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 0.48% probability of exploitation in the next 30 days.
How severe is CVE-2026-43973?
CVE-2026-43973 is rated High with a CVSS score of 8.7. 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-2026-43973?
Yes. A fix has been recorded for CVE-2026-43973. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-43973 affect?
CVE-2026-43973 affects gun (gun_http module), gun < 2.4.0 (1.0.0 to before 2.4.0). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-43973?
Upgrade to gun 2.4.0 or newer
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker can exhaust memory via unbounded HTTP/1.1 buffering, causing node OOM crash.
Patch when possible
- affected>= 1.0.0 and < 2.4.0
- affected>= 11dfe71f4b9aedaaedea2ad3b2f32fd006a8480f and < f3e7e0568b3c4cf9fa4bea79d5116e67ce76ad25
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.