GHSA-hc3c-63hc-2r9f
libcrux: Potential Panic on Overlong Ciphertext Buffer
An application that passes in a ciphertext buffer of length greater
than ptxt.len() + TAG_LEN to libcrux_chacha20poly1305::encrypt or
libcrux_chacha20poly1305::xchacha20_poly1305::encrypt would
experience a panic.
Impact
An application where the length of the ciphertext buffer is under attacker control could be made to crash.
Mitigation
The fix makes it so that libcrux_chacha20poly1305::encrypt and
libcrux_chacha20poly1305::xchacha20_poly1305::encrypt no longer
panic in this case, but instead write out the ciphertext and tag into
the first ptxt.len() + TAG_LEN bytes of the provided buffer.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
What each source reports
GitHub Advisories Score used
libcrux: Potential Panic on Overlong Ciphertext Buffer
An application that passes in a ciphertext buffer of length greater
than ptxt.len() + TAG_LEN to libcrux_chacha20poly1305::encrypt or
libcrux_chacha20poly1305::xchacha20_poly1305::encrypt would
experience a panic.
Impact
An application where the length of the ciphertext buffer is under attacker control could be made to crash.
Mitigation
The fix makes it so that libcrux_chacha20poly1305::encrypt and
libcrux_chacha20poly1305::xchacha20_poly1305::encrypt no longer
panic in this case, but instead write out the ciphertext and tag into
the first ptxt.len() + TAG_LEN bytes of the provided buffer.
- Record
GHSA-hc3c-63hc-2r9f- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-120
- Updated
- 2026-11-02
OSV
libcrux: Potential Panic on Overlong Ciphertext Buffer
An application that passes in a ciphertext buffer of length greater
than ptxt.len() + TAG_LEN to libcrux_chacha20poly1305::encrypt or
libcrux_chacha20poly1305::xchacha20_poly1305::encrypt would
experience a panic.
Impact
An application where the length of the ciphertext buffer is under attacker control could be made to crash.
Mitigation
The fix makes it so that libcrux_chacha20poly1305::encrypt and
libcrux_chacha20poly1305::xchacha20_poly1305::encrypt no longer
panic in this case, but instead write out the ciphertext and tag into
the first ptxt.len() + TAG_LEN bytes of the provided buffer.
- Record
GHSA-hc3c-63hc-2r9f- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-120
- Updated
- 2026-11-02
OSVRUSTSEC-2026-0124
Potential Panic on Overlong Ciphertext Buffer
An application that passes in a ciphertext buffer of length greater
than ptxt.len() + TAG_LEN to libcrux_chacha20poly1305::encrypt or
libcrux_chacha20poly1305::xchacha20_poly1305::encrypt would
experience a panic.
Impact
An application where the length of the ciphertext buffer is under attacker control could be made to crash.
Mitigation
The fix makes it so that libcrux_chacha20poly1305::encrypt and
libcrux_chacha20poly1305::xchacha20_poly1305::encrypt no longer
panic in this case, but instead write out the ciphertext and tag into
the first ptxt.len() + TAG_LEN bytes of the provided buffer.
- Record
RUSTSEC-2026-0124- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libcrux-chacha20poly1305crates.io | before 0.0.8 | 0.0.8 |
libcrux-chacha20poly1305crates.io | 0.0.0-0 up to 0.0.8 | 0.0.8 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | GitHub Advisories, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
GHSA-hc3c-63hc-2r9f is a high vulnerability (CVSS 8.2) in libcrux-chacha20poly1305, published March 29, 2026. No source lists public exploit code. Fixed in libcrux-chacha20poly1305 0.0.8.