CVE-2026-50210 Overview
CVE-2026-50210 documents a cryptographic weakness in a device that encrypts data using Advanced Encryption Standard in Cipher Block Chaining mode (AES-CBC) with a static, zero-filled Initialization Vector (IV). Reusing a fixed IV across encryption operations breaks the semantic security guarantees of CBC mode. Attackers observing ciphertext can correlate identical plaintext blocks across sessions, replay captured traffic, and mount known-plaintext decryption attacks. The flaw is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor. Public technical guidance is referenced through the Acer Community Article.
Critical Impact
An adjacent or network-positioned attacker can decrypt or replay encrypted payloads because the static zero IV eliminates ciphertext randomization across sessions.
Affected Products
- Device referenced in the Acer Community Article
- Specific affected models and firmware versions are not enumerated in the NVD entry
- Components implementing AES-CBC with the documented static IV behavior
Discovery Timeline
- 2026-06-04 - CVE-2026-50210 published to the National Vulnerability Database (NVD)
- 2026-06-04 - Last updated in NVD database
Technical Details for CVE-2026-50210
Vulnerability Analysis
The device implements AES-CBC encryption with an IV consisting entirely of zero bytes for every encryption operation. CBC mode requires a unique, unpredictable IV per message to ensure that encrypting identical plaintexts produces different ciphertexts. When the IV is fixed, the first ciphertext block becomes a deterministic function of the first plaintext block under the same key. Attackers observing repeated traffic can detect equivalent plaintext prefixes and infer structural information about the encrypted data.
The weakness also enables replay attacks. Because the ciphertext is reproducible for identical inputs, captured messages can be replayed to the receiver without modification and will decrypt to the original plaintext. Combined with known-plaintext analysis, an attacker who learns or guesses part of the message contents can recover further plaintext or validate hypotheses about message structure.
Root Cause
The root cause is improper cryptographic initialization. The implementation hardcodes the IV to a zero-filled buffer rather than generating a fresh random value with a cryptographically secure random number generator. This violates the IV uniqueness requirement defined in NIST Special Publication 800-38A for CBC mode.
Attack Vector
The attack vector is network-based and requires no authentication or user interaction. An attacker capable of observing encrypted communications can capture ciphertext for offline analysis, replay previously observed ciphertext to the device, or correlate identical message prefixes across distinct sessions to derive sensitive information.
No verified public exploitation code is referenced in the NVD entry. The vulnerability is described in prose because no realCodeExamples are available for this advisory.
Detection Methods for CVE-2026-50210
Indicators of Compromise
- Repeated identical ciphertext blocks observed in captured traffic between the device and its peers, indicating IV reuse.
- Replay of previously captured encrypted sessions accepted by the device without authentication failure.
- Network flows to or from the affected device containing AES-CBC payloads with deterministic block patterns.
Detection Strategies
- Inspect packet captures for fixed leading 16-byte sequences in encrypted payloads, a signature of static IV usage.
- Compare ciphertexts from successive sessions with similar plaintext prefixes to confirm reuse of the same encryption material.
- Correlate device firmware versions referenced in the Acer Community Article against deployed inventory.
Monitoring Recommendations
- Log and alert on duplicate ciphertext frames seen across distinct authenticated sessions to the same device.
- Monitor for unusual replayed authentication or command sequences arriving from previously seen source addresses.
- Capture baseline encrypted traffic profiles and flag deviations consistent with replay or injection attempts.
How to Mitigate CVE-2026-50210
Immediate Actions Required
- Apply firmware updates from the vendor as referenced in the Acer Community Article once available.
- Restrict network access to the affected device to trusted management segments to reduce exposure to passive interception.
- Rotate any long-lived secrets, tokens, or credentials that may have been transmitted through the affected encryption channel.
Patch Information
Refer to the Acer Community Article for vendor remediation guidance. No specific patched version is listed in the NVD entry at the time of publication.
Workarounds
- Tunnel device communications through an independent transport layer that provides authenticated encryption with per-session IVs, such as TLS 1.3.
- Place the device behind a network segment that prevents untrusted hosts from observing or replaying its traffic.
- Disable affected services or interfaces that rely on the vulnerable encryption routine until a patch is applied.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
