Skip to main content

Content Credentials SDK CVE-2026-95633

| EUVDEUVD-2026-100732 HIGH
Improper Verification of Cryptographic Signature (CWE-347)
2026-10-13 psirt@adobe.com GHSA-6ch8-vmf7-6q8j
7.5
CVSS 3.1 · Vendor: adobe
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Submit content with forged signature
  2. Exploit
    Bypass improper signature verification (CWE-347)
  3. Execution
    Credential accepted as authentic
  4. Impact
    Unauthorized write / falsified provenance

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A04:2025 - Cryptographic Failures
ASVS 5.0
V11 - Cryptography Signature verification
Exploitation Conditions

Exploitation requires a deployment that relies on the CAI Content Credentials SDK to cryptographically verify signatures/claims on content credentials and make trust or write-authorization decisions based on that verification. The core prerequisite is that the attacker can supply content or a token (per the 'Jwt Attack' tag) with a forged or tampered signature to the verification path; the flaw lies in that verifier accepting it. Per the CVSS vector (PR:N/UI:N/AC:L), no authentication, no user interaction, and no special non-default configuration are stated as required, and the attack is network-reachable. The practical limiting factor is scope of use: only systems that actually consume this SDK for signature validation as a security control are exposed, and impact is confined to integrity (no data disclosure or service disruption).

Impact

This is a genuine integrity-focused issue but not an acute emergency. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N, base 7.5) describes a remote, unauthenticated, low-complexity attack with no user interaction and HIGH integrity impact, with zero confidentiality or availability impact - fully consistent with a cryptographic signature-verification bypass (CWE-347) that yields unauthorized write/forgery capability. No EPSS score, KEV listing, POC reference, or SSVC decision data was provided in the input, so exploitation likelihood cannot be quantified from the intelligence available - absence of these signals is not evidence of low risk, only of missing telemetry. The vulnerability was reported through Adobe PSIRT (psirt@adobe.com) and is documented in Adobe advisory APSB26-163, which is a credible first-party source. Net assessment: treat as a real, patch-worthy integrity vulnerability for any deployment relying on Content Credentials for provenance/trust decisions, but its real-world priority is bounded by the fairly specialized footprint of the SDK and by the lack of any confirmed exploitation or public exploit code at the time of analysis.

Exploit ScenarioDerived

An attacker crafts content bearing a forged or manipulated cryptographic signature (the 'Jwt Attack' tag suggests a token/claim-forgery technique) and submits it to a system using the CAI Content Credentials SDK. Because the SDK improperly verifies the signature, the forged credential is accepted as authentic, letting the attacker gain unauthorized write access and falsify provenance metadata remotely without authentication or user interaction. No public exploit code was identified in the provided intelligence.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.5% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Oct 13, 2026

A signature-verification bypass in the CAI Content Credentials SDK allows an unauthenticated, network-reachable attacker to submit content or a token bearing a forged or tampered cryptographic signature that the SDK's verifier accepts, yielding unauthorized write access to systems that rely on that verification as a trust decision. Per the CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N) the attack needs no credentials and no user interaction, and the assessment confines impact to integrity only, with no confidentiality or availability loss. The practical exposure is narrow but real: only deployments that actually consume the SDK to validate signatures or claims as a security control are affected, and no public exploit code was identified at time of analysis, so this is a genuine integrity issue rather than an acute emergency.

RemediationAI

No exact fix version is present in the provided intelligence, so patch status should be confirmed against Adobe's advisory APSB26-163 (https://www.adobe.com/trust/security/products/content-credentials-sdk/apsb26-163.html) and the vendor-designated fixed SDK release applied as the primary remediation; do not treat absence of a version in this analysis as confirmation that no update exists. If immediate upgrade is not possible, compensate at the verification boundary: enforce a strict allowlist of expected signing algorithms and key types in the calling code and reject 'none'/unsigned and algorithm-confusion (HMAC vs. asymmetric) cases before or in addition to the SDK call - trade-off: legitimate credentials produced with unlisted algorithms will be rejected; pin the expected issuer and public keys instead of resolving keys dynamically from credential-supplied metadata - trade-off: key rotation requires configuration updates; additionally validate the full credential chain, timestamp/claim bindings, and any asset-to-credential binding rather than trusting a boolean SDK verdict, and treat credentials as untrusted input anywhere they gate write or publish authorization - trade-off: added validation latency and integration work. Where signatures cannot be verified reliably, fall back to requiring authenticated application-level authorization for write operations so a forged credential alone cannot grant access, and monitor logs for rejected or anomalous credential submissions to detect attempted abuse.

Affected VersionsENISA

Content Credentials JS SDK 0 ≤@contentauth/c2pa-web@0.13.4
C2PA Tool 0 ≤c2patool-v0.27.15
Content Credentials Rust SDK 0 ≤c2pa-v0.90.15

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The vulnerability is a CWE-347 Improper Verification of Cryptographic Signature flaw in Adobe/CAI Content Credentials, the provenance and authenticity framework (Content Authenticity Initiative) used to attach cryptographically signed manifests - content credentials - to images, video, and other media so downstream systems can verify who made or modified them. The weakness sits in the verifier logic rather than in the signing side: the SDK fails to properly validate the signature over the credential claims, so a forged or tampered credential passes validation. The 'Jwt Attack' tag indicates the abuse pattern resembles well-known JWT verification failures, such as accepting an unexpected or unsigned algorithm (alg:none), algorithm-confusion between HMAC and asymmetric algorithms, incorrect key/issuer binding, or failures to validate the signature over the full claim set and chain of trust. Because the CVSS vector is PR:N/UI:N/AC:L/S:U, no authentication, no user interaction, and no non-default configuration are prerequisites, and the flaw is remotely reachable over the network; the limiting factor is deployment scope, since the flaw is only exploitable where an application actually feeds attacker-supplied credentials or tokens into the SDK's verification path and acts on the result (for example, to grant write or publish authorization).

Know when Jwt Attack gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

Vendor (adobe) PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
vuln.today AI 7.5 HIGH

Signature-verification bypass is remotely reachable with no auth or interaction (AV:N/AC:L/PR:N/UI:N); it grants forgery/write capability so I:H, with no confidentiality or availability effect (C:N/A:N).

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (adobe).

CVSS VectorVendor: adobe

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

DescriptionCVE.org

CAI Content Credentials is affected by an Improper Verification of Cryptographic Signature vulnerability that could result in a Security feature bypass. An attacker could leverage this vulnerability to bypass security measures and gain unauthorized write access. Exploitation of this issue does not require user interaction.

Executive ViewAI

Why It Matters

A signature-verification bypass in the CAI Content Credentials SDK allows an unauthenticated, network-reachable attacker to submit content or tokens bearing forged cryptographic signatures that the SDK's verifier accepts as genuine, corrupting the trust decision that gates unauthorized write access in the systems consuming it. Only organizations that rely on the SDK to validate signatures or claims as a security control are exposed, and impact is confined to integrity - no confidentiality or availability loss - so this is a targeted trust-correctness problem rather than an enterprise-wide disruption risk. Leadership should care because any workflow that automatically acts on 'verified' content, such as publishing, provenance attestation, or authorization grants, can be manipulated without credentials or user interaction.

Business Impact: Medium
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations: treat a passing SDK signature verification as insufficient on its own and require an independent, out-of-band validation of content or token authenticity before any write, publish, or authorization action is allowed; enforce manual review or dual approval for high-consequence trust decisions; restrict network access to services that expose SDK verification to trusted networks and segments; log and alert on all verification events and on submissions from unexpected sources; monitor the vendor advisory and CISA KEV feed for a fixed version and patch immediately once released.

Threat Intelligence Overview

EPSS Score
0.5%
Top 62% exploitable
Prevalence
Low
specialized content-provenance SDK, limited production deployment footprint
Social Media
1
Sightings
Data Quality
4 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.5%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
Yes
Human Impact
Medium
Technical Impact
Partial

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

CVE-2013-3900 MEDIUM
5.5 Dec 11

Why is Microsoft republishing a CVE from 2013? We are republishing CVE-2013-3900 in the Security Update Guide to update

CVE-2026-48558 CRITICAL POC
9.5 Jun 12

Authentication bypass in SimpleHelp 5.5.15 and prior (plus 6.0 pre-release builds) allows remote unauthenticated attacke

CVE-2026-5430 CRITICAL POC
10.0 Aug 06

Authentication bypass in WSO2 API Manager and related components (Universal Gateway, Traffic Manager, API Control Plane,

CVE-2025-59718 CRITICAL
9.8 Dec 09

Authentication bypass in Fortinet FortiOS, FortiProxy, and FortiSwitchManager allows unauthenticated remote attackers to

CVE-2025-25291 CRITICAL POC
9.3 Mar 12

ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. Rated critical severity (CVS

CVE-2025-25292 CRITICAL POC
9.3 Mar 12

ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. Rated critical severity (CVS

CVE-2022-25898 CRITICAL POC
9.8 Jul 01

The package jsrsasign before 10.5.25 are vulnerable to Improper Verification of Cryptographic Signature when JWS or JWT

CVE-2026-107722 CRITICAL POC
9.8 Oct 08

Authentication and authorization bypass in fast-jwt 6.2.0 through 6.2.4 (npm, NearForm) lets a remote, unauthenticated a

CVE-2024-42004 CRITICAL POC
9.8 Dec 18

A library injection vulnerability exists in Microsoft Teams (work or school) 24046.2813.2770.1094 for macOS. Rated criti

CVE-2024-41145 CRITICAL POC
9.8 Dec 18

A library injection vulnerability exists in the WebView.app helper app of Microsoft Teams (work or school) 24046.2813.27

CVE-2024-41138 CRITICAL POC
9.8 Dec 18

A library injection vulnerability exists in the com.microsoft.teams2.modulehost.app helper app of Microsoft Teams (work

CVE-2024-45409 CRITICAL POC
9.8 Sep 10

The Ruby SAML library is for implementing the client side of a SAML authorization. Rated critical severity (CVSS 9.8), t

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy