Core PHP vulnerability affecting widely deployed PHP 8.x releases; enables trivial SQLi across web applications, likely to impact many organizations and needs broad IT attention.
CVE-2026-17543
SQL injection in PHP 8.2–8.5 via improper backslash escaping.
Is CVE-2026-17543 being exploited?
Not confirmed. CVE-2026-17543 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 0.32% probability of exploitation in the next 30 days.
How severe is CVE-2026-17543?
CVE-2026-17543 is rated High with a CVSS score of 8.1. 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-2026-17543?
Yes. A fix has been recorded for CVE-2026-17543. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-17543 affect?
CVE-2026-17543 affects PHP 8.2 before 8.2.33, PHP 8.3 before 8.3.33, PHP 8.4 before 8.4.24, PHP 8.5 before 8.5.9. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-17543?
Upgrade PHP to the listed fixed versions or apply vendor patches immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote SQL injection via crafted parameters allowing data exfiltration, DB modification, auth bypass and compromise of PHP web apps.
Immediate action required
- affected>= 8.2.* and < 8.2.33
- affected>= 8.3.* and < 8.3.33
- affected>= 8.4.* and < 8.4.24
- affected>= 8.5.* and < 8.5.9
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.