CVE-2023-5256 | Drupal core - Critical - Cache poisoning - SA-CORE-2023-006

In certain scenarios, Drupal's JSON:API module will output error backtraces. With some configurations, this may cause sensitive information to be cached and made available to anonymous users, leading to privilege escalation. This vulnerability only affects sites with the JSON:API module enabled, and can be mitigated by uninstalling JSON:API. The core REST and contributed GraphQL modules are not affected.

Published: 2023-09-28 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-5256 is rated Moderate Risk (46.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.69%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-5256

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.29% 0.69% -0.60%
2 2026-03-04 0.62% 1.29% +0.67%
3 2026-03-01 — 0.62% —

Full EPSS history (52 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-5256

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.6 5.9 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.6 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2023-5256

GitHub Security Advisory for CVE-2023-5256

GHSA-rjqg-3h9m-fx5x · Severity: critical · Ecosystem: composer — Cache poisoning in drupal/core

OS Trackers for CVE-2023-5256

vendor priority summary link
ubuntu medium CVE-2023-5256 medium priority: Ubuntu including 1 source packages (drupal7), 9 status rows across 9 suites (focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 6, needs-triage 3. https://ubuntu.com/security/CVE-2023-5256

Affected software / configurations for CVE-2023-5256

Vendor Product Version Raw CPE
drupal drupal >= 8.7.0, < 9.5.11 cpe:2.3:a:drupal:drupal:*:*:*:*:*:*:*:*
drupal drupal >= 10.0.0, < 10.0.11 cpe:2.3:a:drupal:drupal:*:*:*:*:*:*:*:*
drupal drupal >= 10.1.0, < 10.1.4 cpe:2.3:a:drupal:drupal:*:*:*:*:*:*:*:*

References for CVE-2023-5256

URL Tags
https://www.drupal.org/sa-core-2023-006 Vendor Advisory
cvelogic Threat Intelligence