Plaintext recovery via AES-GCM counter wrap
Published Jun 25, 2026 · Updated Jun 25, 2026
Cryptographic failure in wolfSSL 4.8.0 through 5.9.1 allows local users to recover plaintext from oversized AES-GCM streams. In wolfcrypt/src/aes.c, wc_AesGcmEncryptUpdate() and wc_AesGcmDecryptUpdate() accumulated message length without rejecting 32-bit counter exhaustion, so inputs exceeding 64 GiB wrapped the GCM counter and reused keystream. Exploitation requires low-privileged local access, a single streaming operation exceeding 64 GiB, and control or observation sufficient to derive plaintext; integrity and availability are not affected.
Summary
What happened
Cryptographic failure in wolfSSL 4.8.0 through 5.9.1 allows local users to recover plaintext from oversized AES-GCM streams. In wolfcrypt/src/aes.c, wc_AesGcmEncryptUpdate() and wc_AesGcmDecryptUpdate() accumulated message length without rejecting 32-bit counter exhaustion, so inputs exceeding 64 GiB wrapped the GCM counter and reused keystream. Exploitation requires low-privileged local access, a single streaming operation exceeding 64 GiB, and control or observation sufficient to derive plaintext; integrity and availability are not affected.
The record
- CVE
- CVE-2026-55967
- Published
- Jun 25, 2026
- Updated
- Jun 25, 2026
- Vendor
- wolfSSL
- Product
- wolfSSL
- Classifications
- CWE-323
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 25, 2026CVE publishedPublication date reported by the CVE source.
- Jun 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.8.0 <=5.9.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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