CVE-2025-40925
Starch versions 0.14 and earlier generate session ids insecurely
Starch versions 0.14 and earlier generate session ids insecurely.
The default session id generator returns a SHA-1 hash seeded with a counter, the epoch time, the built-in rand function, the PID, and internal Perl reference addresses. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.
Predicable session ids could allow an attacker to gain access to systems.
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
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
9.1
Starch versions 0.14 and earlier generate session ids insecurely
Starch versions 0.14 and earlier generate session ids insecurely.
The default session id generator returns a SHA-1 hash seeded with a counter, the epoch time, the built-in rand function, the PID, and internal Perl reference addresses. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.
Predicable session ids could allow an attacker to gain access to systems.
- Record
CVE-2025-40925- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-340, CWE-338
- Updated
- 2026-11-02
EUVDEUVD-2025-30364
9.1
Starch versions 0.14 and earlier generate session ids insecurely.
The default session id generator returns a SHA-1 hash seeded with a counter, the epoch time, the built-in rand function, the PID, and internal Perl reference addresses. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.
Predicable session ids could allow an attacker to gain access to systems.
- Record
EUVD-2025-30364- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-q46q-p96m-rvh8
9.1
Starch versions 0.14 and earlier generate session ids insecurely. The default session id...
Starch versions 0.14 and earlier generate session ids insecurely.
The default session id generator returns a SHA-1 hash seeded with a counter, the epoch time, the built-in rand function, the PID, and internal Perl reference addresses. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.
Predicable session ids could allow an attacker to gain access to systems.
- Record
GHSA-q46q-p96m-rvh8- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-338
- Updated
- 2026-11-02
NVD
9.1
Starch versions 0.14 and earlier generate session ids insecurely.
The default session id generator returns a SHA-1 hash seeded with a counter, the epoch time, the built-in rand function, the PID, and internal Perl reference addresses. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.
Predicable session ids could allow an attacker to gain access to systems.
- Record
CVE-2025-40925- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-338, CWE-340
- Updated
- 2026-11-02
OSV
9.1
Starch versions 0.14 and earlier generate session ids insecurely
Starch versions 0.14 and earlier generate session ids insecurely.
The default session id generator returns a SHA-1 hash seeded with a counter, the epoch time, the built-in rand function, the PID, and internal Perl reference addresses. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.
Predicable session ids could allow an attacker to gain access to systems.
- Record
CVE-2025-40925- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-338, CWE-340
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-40925 is a critical vulnerability (CVSS 9.1) in Bluefeet Starch, published September 20, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.36%, the 29th percentile. No source names a fixed version.
References
github.com/bluefeet/Starch/pull/5
github.com/bluefeet/Starch/commit/5573449e64e0660f7ee209d1eab5881d4ccbee3b.patch
metacpan.org/dist/Starch/source/lib/Starch/Manager.pm
nvd.nist.gov/vuln/detail/CVE-2025-40925
github.com/advisories/GHSA-q46q-p96m-rvh8
cpan.org/modules
github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40925.json
github.com/bluefeet/Starch