CVE-2026-117656：Sign in with Apple 回呼引數可覆蓋 ID Token，允許偽造使用者身份
CVE-2026-117656 - Unverified Sign in with Apple callback parameter can override verified ID token claims
此漏洞使未授權遠端攻擊者可利用 Sign in with Apple 的回呼引數覆蓋驗證過的 ID Token，進而偽造使用者身份。
- 受影響產品：pow‑auth 的 assent，0.1.25 之前至 0.3.2 之前。
Acceptance of Extraneous Untrusted Data With Trusted Data vulnerability in the Sign in with Apple strategy in pow-auth Assent allows an unauthenticated remote attacker to impersonate another user via the user parameter of the authorization callback. Apple posts the user's name to the callback endpoint in a user form parameter that the browser submits and the client controls. Assent.Strategy.Apple.callback/2 in lib/assent/strategies/apple.ex decodes that parameter, and fetch_user/2 merges it over the claims of the verified ID token, so the unverified map wins. An attacker who completes a Sign in with Apple login with their own Apple ID and edits the user parameter can replace sub, email, and any other claim. Applications that look up, link, or authorize accounts by the returned subject or email then act on the attacker's values. This issue affects assent: from 0.1.25 before 0.3.2.
Impact
Affected Products
The following products are affected by CVE-2026-117656
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
| ID | Vendor | Product | Action |
|---|---|---|---|
| 1 | Pow-auth | assent |
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | CRITICAL | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | ||||
| CVSS 4.0 | CRITICAL | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db |
Update assent to version 0.3.2 or later to fix user impersonation vulnerability.
- Update assent to version 0.3.2 or later.
- Verify authentication logic handles user data securely.
- Validate user identifiers after authentication.
- Apply security updates promptly.
Here, you will find a curated list of external links that provide in-depth
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CVE-2026-117656.
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-117656 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-117656
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-117656 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-117656 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
十月. 31, 2026
Action Type Old Value New Value Added Description Acceptance of Extraneous Untrusted Data With Trusted Data vulnerability in the Sign in with Apple strategy in pow-auth Assent allows an unauthenticated remote attacker to impersonate another user via the user parameter of the authorization callback. Apple posts the user's name to the callback endpoint in a user form parameter that the browser submits and the client controls. Assent.Strategy.Apple.callback/2 in lib/assent/strategies/apple.ex decodes that parameter, and fetch_user/2 merges it over the claims of the verified ID token, so the unverified map wins. An attacker who completes a Sign in with Apple login with their own Apple ID and edits the user parameter can replace sub, email, and any other claim. Applications that look up, link, or authorize accounts by the returned subject or email then act on the attacker's values. This issue affects assent: from 0.1.25 before 0.3.2. Added CVSS V4.0 AV:N/AC:L/AT:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-290 Added CWE CWE-349 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/117xxx/CVE-2026-117656.json">CVE-2026-117656</a> Added Reference https://cna.erlef.org/cves/CVE-2026-117656.html Added Reference https://github.com/pow-auth/assent/commit/18898bde0296152165ae470078490e5798329b1b Added Reference https://github.com/pow-auth/assent/commit/a2d331e8c51376d6c0b04a81aad31e0b4d4d64a3 Added Reference https://github.com/pow-auth/assent/security/advisories/GHSA-9fr5-g44g-9526 Added Reference https://osv.dev/vulnerability/EEF-CVE-2026-117656
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.