SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityReceived

CVE-2026-48717

Because that setting is disabled by default, an attacker who intercepts a PKCE-protected authorization code can omit code_verifier and redeem the code, while an explicitly incorrect verifier is rejected.

CRITICAL 9.1EPSS 0.33%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.33%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Open Access Management (OpenAM) is an access management solution. Prior to 16.1.1, AuthorizationCodeGrantTypeHandler requires a code_verifier only when the realm-wide codeVerifierEnforced setting is enabled, even when an authorization code stores a code_challenge. Because that setting is disabled by default, an attacker who intercepts a PKCE-protected authorization code can omit code_verifier and redeem the code, while an explicitly incorrect verifier is rejected. Public clients are directly affected, and confidential-client exploitation additionally requires client authentication material or another redemption context. This issue is fixed in version 16.1.1.

CVSS 4.0
9.1 CRITICALCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.33% probability · 26th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-285
Source
security-advisories@github.com
EPSS trend
0%3%5%19 September 2026: 0.33%19 September 202619 September 2026

EPSS 0.3% since 19 September 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.