CVE-2026-31908
Header injection via forward-auth in Apache APISIX (2.12.0–3.15.0).
Is CVE-2026-31908 being exploited?
Not confirmed. CVE-2026-31908 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 0.52% probability of exploitation in the next 30 days.
How severe is CVE-2026-31908?
CVE-2026-31908 is rated Critical with a CVSS score of 9.1. 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-2026-31908?
Yes. A fix has been recorded for CVE-2026-31908. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-31908 affect?
CVE-2026-31908 affects Apache APISIX. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-31908?
Upgrade to Apache APISIX 3.16.0
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Header injection enables crafting/modifying headers via forward-auth, potentially bypassing auth checks and tampering requests.
Patch when possible
- affected>= 2.12.0 and <= 3.15.0
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.