CVE-2026-123870
[Eclipse CSI - otterdog] Unauthenticated remote code execution via eval() on format-string-injected webhook body when GITHUB_WEBHOOK_SECRET is unset
CVE-2026-123870 is a critical vulnerability (CVSS 9.5) in Eclipse Foundation Otterdog, published November 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.30%, the 23rd percentile. No source names a fixed version.
- Severity
- 9.5 CriticalCVSS 4.0, CVE List
- Exploit chance
- 0.30%EPSS, 23rd percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
Description
The otterdog webapp evaluates a format-string built from the incoming GitHub webhook JSON body using Python's eval(). When the GITHUB_WEBHOOK_SECRET configuration value is unset or empty (the code default is None), the HMAC signature check is skipped entirely, allowing an unauthenticated network client to reach the eval() sink with attacker-controlled input and execute arbitrary Python on the webapp host.
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
- High
Exploit likelihood
Discussion
Affected products
What each source reports
CVE List Score used
[Eclipse CSI - otterdog] Unauthenticated remote code execution via eval() on format-string-injected webhook body when GITHUB_WEBHOOK_SECRET is unset
The otterdog webapp evaluates a format-string built from the incoming GitHub webhook JSON body using Python's eval(). When the GITHUB_WEBHOOK_SECRET configuration value is unset or empty (the code default is None), the HMAC signature check is skipped entirely, allowing an unauthenticated network client to reach the eval() sink with attacker-controlled input and execute arbitrary Python on the webapp host.
- Record
CVE-2026-123870- CVSS 4.0
- 9.5 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - Weakness
- CWE-95
- Updated
- 2026-11-12
EUVDEUVD-2026-119883
The otterdog webapp evaluates a format-string built from the incoming GitHub webhook JSON body using Python's eval(). When the GITHUB_WEBHOOK_SECRET configuration value is unset or empty (the code default is None), the HMAC signature check is skipped entirely, allowing an unauthenticated network client to reach the eval() sink with attacker-controlled input and execute arbitrary Python on the webapp host.
- Record
EUVD-2026-119883- CVSS 4.0
- 9.5 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - Updated
- 2026-11-09
NVD
The otterdog webapp evaluates a format-string built from the incoming GitHub webhook JSON body using Python's eval(). When the GITHUB_WEBHOOK_SECRET configuration value is unset or empty (the code default is None), the HMAC signature check is skipped entirely, allowing an unauthenticated network client to reach the eval() sink with attacker-controlled input and execute arbitrary Python on the webapp host.
- Record
CVE-2026-123870- CVSS 4.0
- 9.5 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-95
- Updated
- 2026-11-12
OSV
[Eclipse CSI - otterdog] Unauthenticated remote code execution via eval() on format-string-injected webhook body when GITHUB_WEBHOOK_SECRET is unset
The otterdog webapp evaluates a format-string built from the incoming GitHub webhook JSON body using Python's eval(). When the GITHUB_WEBHOOK_SECRET configuration value is unset or empty (the code default is None), the HMAC signature check is skipped entirely, allowing an unauthenticated network client to reach the eval() sink with attacker-controlled input and execute arbitrary Python on the webapp host.
- Record
CVE-2026-123870- CVSS 4.0
- 9.5 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - Weakness
- CWE-95
- Updated
- 2026-11-11
History
| Recorded | Changed | Sources |
|---|---|---|
| references | CVE List | |
| references | OSV | |
| aliases, references | NVD, OSV | |
| aliases, published | EUVD | |
| first indexed | CVE List |
Dates are when Every CVE recorded each change. Upstream dates may differ.
References
gitlab.eclipse.org/security/cve-assignment/-/work_items/554
github.com/eclipse-csi/otterdog/security/advisories/GHSA-32xf-7j44-xq72
pypi.org
nvd.nist.gov/vuln/detail/CVE-2026-123870