CVE-2026-81688: openssl_encrypt versions before 1.4.9 store an unkeyed SHA-256 hash of the plaintext in the cleartext file hea
CVE-2026-81688 is a high-severity flaw (CVSS 7.5) affecting openssl encrypt. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
openssl_encrypt versions before 1.4.9 store an unkeyed SHA-256 hash of the plaintext in the cleartext file header metadata. Attackers can read this hash without the password to confirm guessed plaintexts offline or fingerprint identical plaintexts across separately-encrypted files.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 81%) |
| CISA exploited list | No |
| Weakness | CWE-311 |
| Published | 2026-08-27 |
| Last modified | 2026-09-02 |
Last updated 2026-09-02 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-81688?
openssl encrypt: upgrade to 1.4.9. Exact commands for each OS are on this page.
Is CVE-2026-81688 being exploited?
CVE-2026-81688 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-81688 affect?
CVE-2026-81688 affects openssl encrypt. Severity is high (CVSS 7.5). openssl_encrypt versions before 1.4.9 store an unkeyed SHA-256 hash of the plaintext in the cleartext file header metadata. Attackers can read this hash without the password to confirm guessed plaintexts offline or fingerprint identical pla
How urgent is CVE-2026-81688?
Priority 41/100. High severity; Remotely exploitable, no login, no user action; On your watchlist
Software pages
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