VulnerabilityPublished 10 Nov 2025Updated 14 Nov 2025

CVE-2025-64484: oauth2-proxy · Improper Neutralization of HTTP Headers for Scripting Syntax

Affects oauth2-proxySource GCVE Database

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Not known to be exploited · CVSS 8.5 High : upgrade to 7.13.0 soon.

Data as of 13 Nov 2026, 18:56 UTC

CVSS 3.1 base score

8.5High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	8.5

Patch: Available – fixed in 7.13.0

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade oauth2-proxy to 7.13.0.

Affected software

Product	Affected	Fixed in
oauth2-proxy oauth2-proxy	Affected <7.13.0	Fixed in 7.13.0

AI-suggested

Upgrade oauth2-proxy to version 7.13.0 or later, where this vulnerability is fixed by normalizing header names during filtering to treat underscores and dashes equivalently. If upgrading immediately is not possible, ensure that upstream services do not treat underscores and dashes in HTTP headers as equivalent to prevent bypass. Additionally, review and adjust header filtering logic in upstream applications. The new configuration option 'InsecureSkipHeaderNormalization' can be used to disable normalization if necessary, but this should be done with caution. No other actions are required once patched.

Description

CVE-2025-64484 is a high-severity vulnerability in oauth2-proxy versions prior to 7.13.0. It involves improper neutralization of HTTP headers for scripting syntax, specifically allowing authenticated users to inject underscore variants of X-Forwarded-* headers. This bypasses the proxy's filtering logic in environments where upstream applications normalize underscores to dashes in HTTP headers, potentially leading to privilege escalation in the upstream app. The vulnerability does not compromise oauth2-proxy's own authentication or authorization mechanisms. The issue is fixed in version 7.13.0, which normalizes headers by ignoring capitalization and underscore versus dash differences when stripping headers. A configuration option is available for users who need to disable this normalization. As a workaround, upstream services should ensure their header filtering logic treats underscores and dashes distinctly.

Impact

Authenticated users can bypass oauth2-proxy's header filtering by injecting underscore variants of X-Forwarded-* headers, which may lead to privilege escalation in upstream applications that normalize underscores to dashes in HTTP headers. This can compromise the security context or access control of the upstream app. The oauth2-proxy authentication and authorization mechanisms themselves remain secure and unaffected. The CVSS score of 8.5 reflects a high impact with network attack vector, low attack complexity, requiring privileges, no user interaction, and partial confidentiality and integrity impact without availability impact.

Summary

OAuth2-Proxy versions before 7.13.0 are vulnerable to improper neutralization of HTTP headers (CWE-644) due to inconsistent handling of underscores and dashes in header names. Authenticated users can exploit this by injecting underscore variants of X-Forwarded-* headers, bypassing the proxy's filtering and potentially escalating privileges in upstream applications that normalize underscores to dashes (e.g., WSGI frameworks like Django, Flask, FastAPI, and PHP apps). The vulnerability does not affect oauth2-proxy's authentication or authorization directly. The fix in version 7.13.0 enforces normalization of headers during filtering, treating headers with underscores and dashes equivalently, thus preventing bypass. An optional configuration allows disabling this normalization if needed. Upstream services are advised to differentiate underscores and dashes in header processing as a mitigation.

CWE-644Improper Neutralization of HTTP Headers for Scripting Syntax (opens in a new tab)
Variant weaknessLikelihood of exploit: HighOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes web scripting syntax in HTTP headers that can be used by web browser components that can process raw headers, such as Flash.
Architecture and Design
Carefully control data that is being placed both in HTTP response headers and in the HTTP response body to ensure that no scripting syntax is present, taking various encodings into account.
Architecture and Design
Disable script execution functionality in the clients' browser.
OWASP Cheat Sheets
Content Security Policy (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
Query Parameterization (opens in a new tab)
OWASP ASVS 4.0.3
V14.4.6 (opens in a new tab)
V14.4.4 (opens in a new tab)
V14.4.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Affected software

Description

AI analysisMachine-generated, updated 13 Nov 2026, 18:56 UTC

WeaknessesCWE-644

Technical details

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