PatchTheCEVCVE-2026-17543: Improper escaping of backslashes in attacker-provided parameters would allow for trivial SQL injection in PHP
49
This month
CRITICAL 9.8REMOTEUPGRADE
CVE-2026-17543 is a critical-severity flaw (CVSS 9.8) affecting php. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Improper escaping of backslashes in attacker-provided parameters would allow for trivial SQL injection in PHP versions from 8.2.* before 8.2.33, from 8.3.* before 8.3.33, from 8.4.* before 8.4.24, and from 8.5.* before 8.5.9.
Why this priority
- Critical severity
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 75%) |
| CISA exploited list | No |
| Weakness | CWE-89 |
| Published | 2026-07-30 |
| Last modified | 2026-10-23 |
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
php php UPGRADE
Affected: >= 8.2.0 and < 8.2.33 · >= 8.3.0 and < 8.3.33 · >= 8.4.0 and < 8.4.24 · >= 8.5.0 and < 8.5.9
Fixed in: 8.2.33, 8.3.33, 8.4.24, 8.5.9
Safe to downgrade to: a release before 8.2.0
1. Check installed version
apt-cache policy php || rpm -q php || php --version
2. UPGRADE to 8.2.33 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade php
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade php
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 8.2.0 (Debian / Ubuntu)
apt-cache madison php
sudo apt install php=<VERSION_BEFORE_8.2.0>
sudo apt-mark hold php
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list php
sudo dnf downgrade php-<VERSION_BEFORE_8.2.0>
sudo dnf versionlock add php
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
Exact fixes by distribution
Fedora 46 · rubygem-eventmachine · FIXED · 1.2.7-37.fc46 · FEDORA-2026-7194c202a2 · source
sudo dnf upgrade --advisory=FEDORA-2026-7194c202a2
Debian 12 · php8.2 · FIXED · 8.2.33-1~deb12u1
sudo apt update && sudo apt install --only-upgrade php8.2
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' php8.2)" ge "8.2.33-1~deb12u1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · php8.4 · FIXED · 8.4.24-1~deb13u1
sudo apt update && sudo apt install --only-upgrade php8.4
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' php8.4)" ge "8.4.24-1~deb13u1" && echo PATCHED || echo STILL-VULNERABLE
RHEL 10 · php8.4 · FIXED · php8.4-8.4.24-1.el10_2
sudo dnf upgrade --advisory=RHSA-2026:56969
rpm -q php8.4
RHEL 10 · php · FIXED · php-8.3.33-1.el10_2
sudo dnf upgrade --advisory=RHSA-2026:62614
rpm -q php
RHEL 9 · php · FIXED · php-8.0.30-8.el9_8
sudo dnf upgrade --advisory=RHSA-2026:61259
rpm -q php
RHEL 6 · php · DEFERRED
RHEL 7 · php · NOT AFFECTED
Alpine 3.22 · php82 · FIXED · php82-8.2.33-r0
apk add --upgrade php82
apk info -v php82
Alpine 3.22 · php83 · FIXED · php83-8.3.36-r0
apk add --upgrade php83
apk info -v php83
Alpine 3.22 · php84 · FIXED · php84-8.4.27-r0
apk add --upgrade php84
apk info -v php84
Alpine 3.23 · php83 · FIXED · php83-8.3.36-r0
apk add --upgrade php83
apk info -v php83
sudo dnf update --advisory=ALAS2023-2026-2044
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- GitHub PoC: Hunt-Benito/e-is-for-exploit-cve-2026-17543-php-pgsql-sql-injection-backslash-breakout (1 stars)
- GitHub PoC: pratham220/CVE-2026-17543-PHP-Exposure-Validator (0 stars)
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Related CVEs
- CVE-2026-17544 CRITICAL 9.8 UPGRADE Attacker-provided inputs to bccomp() could lead to an out-of-bounds write with stack and heap corruption in PH
- CVE-2026-7260 MEDIUM 5.5 UPGRADE Circular symbolic links in phar archives could lead to unbounded recursion, exhausting the C stack and crashin
- CVE-2026-109618 CRITICAL 9.8 UPGRADE MITIGATE PHP uses longjmp() for out-of-memory (OOM) errors to exit the current context and abort handling of the reques
- CVE-2026-109619 HIGH 8.1 UPGRADE MITIGATE PHP has various global state that temporarily points into request memory
- CVE-2026-93682 MEDIUM 5.8 UPGRADE When the HTTP stream wrapper follows a redirect and the response carries a Location header with an empty value