Valve Source SDK Stack-Based Buffer Overflow RCE
Published Oct 15, 2025
9.2
CRITICALCVSS 4.0
EPSS 0.69%
Description
Valve's Source SDK (source-sdk-2013)'s ragdoll model parsing logic contains a stack-based buffer overflow vulnerability.The tokenizer function `nexttoken` copies characters from an input string into a fixed-size stack buffer without performing bounds checks. When `ParseKeyValue` processes a collisionpair rule longer than the destination buffer (256 bytes), an overflow of the stack buffer `szToken` can occur and overwrite the function return address. A remote attacker can trigger the vulnerable code by supplying a specially crafted ragdoll model which causes the oversized collisionpair rule to be parsed, resulting in remote code execution on affected clients or servers. Valve has addressed this issue in many of their Source games, but independently-developed games must manually apply patch.
Affected products
-
- Version source-sdk-2013StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Valve Software | Source SDK (source-sdk-2013) | unaffected |
|
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
1 other source (NVD) ▾
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/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
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
TotalDecision
n/aAssessed Oct 15, 2025 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2025–2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.69% (0.00693) | 51.14th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.63% (0.00632) | 45.32th | v5 (v2026.06.15) |
| Oct 15, 2025 | 0.37% (0.00370) | 58.07th | v4 (v2025.03.14) |
References (3)
- https://github.com/ValveSoftware/source-sdk-2013 product
- https://www.oneupsecurity.com/research/remote-code-execution-in-source-games/ technical-descriptionpatch
- https://www.vulncheck.com/advisories/valve-source-sdk-stack-based-buffer-overflow-rce third-party-advisory
| Link | Providers | Tags |
|---|---|---|
| https://github.com/ValveSoftware/source-sdk-2013 | product | |
| https://www.oneupsecurity.com/research/remote-code-execution-in-source-games/ | technical-descriptionpatch | |
| https://www.vulncheck.com/advisories/valve-source-sdk-stack-based-buffer-overflow-rce | third-party-advisory |
Change history (0)
No recorded changes yet.