CVE-2026-105963: Secret key base exposed in stack trace arguments on wrong-typed Plug.Crypto arguments
Noroxi assessment
Priority: Monitor (action score 20/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.50% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: elixir-plug plug 1.7.0; elixir-plug plug_crypto 2.2.1, 981887493dada0fce7003c61861c00dfbb0fc8c5.
Low priority for now. Upgrade to elixir-plug plug 1.7.0; elixir-plug plug_crypto 2.2.1, 981887493dada0fce7003c61861c00dfbb0fc8c5 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Externally-Generated Error Message Containing Sensitive Information vulnerability in plug_crypto in elixir-plug plug_crypto allows an unauthenticated remote attacker to expose the secret key base through application logs via a wrong-typed argument. Every public function in Plug.Crypto validates argument types in a function-head guard. A failed guard makes the Erlang VM raise FunctionClauseError with the actual argument values in the top stack frame, so the secret key base, a derived key, or the value an API key is compared against lands in that frame. The library's rescue blocks and Plug.Crypto.prune_args_from_stacktrace/1 only reach exceptions raised inside a function body, so they never see a guard failure. Plug.Cowboy and Bandit write the frame to the error log and attach it as crash_reason Logger metadata, which error trackers forward. Two entry points take request data. Plug.Crypto.verify/4 exposes the secret key base when the token is neither a binary nor nil, which Phoenix.Token.verify/4 reaches because it forwards the token unguarded. Plug.Crypto.secure_compare/2 exposes the other operand when one side is not a binary, as happens when a missing request header yields nil. Reading the leaked value needs separate access to the logs or the error tracker, so the request alone does not disclose the secret to the attacker. This issue affects plug: from 1.6.3 before 1.7.0; plug_crypto: from 1.0.0 before 2.2.1.
- Published
- Oct 23, 2026
- Updated
- Oct 23, 2026
- EPSS
- 0.5% · 43th percentile
- CWE
- CWE-532
Report tools
Action score
20
Low priority for now.
- CVSS
- 20 / 40 · 5.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · EEF
- 5.1
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (EEF). Independent of NVD's CPE analysis and usually ahead of it.
elixir-plug plug
- 1.6.3 and later · before 1.7.0affected · semver
- 56000c33d8a0a2fbac491f8be06b9c5112bc2276 and lateraffected · git
elixir-plug plug_crypto
- 1.0.0 and later · before 2.2.1affected · semver
- 2d078b7b8264c565f0ff71235c515f4f46882dcf and later · before 981887493dada0fce7003c61861c00dfbb0fc8c5affected · git
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Hex | plug | from 1.6.3 · before 1.7.0 | 1.7.0 |
| Hex | plug_crypto | from 1.0.0 · before 2.2.1 | 2.2.1 |
Same product
elixir-plug: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-54892Plug: quadratic-time decoding of nested query/body parameters enables denial of service34Monitor
- CVE-2026-8468Unbounded buffer accumulation in multipart header parsing causes denial of service in plug32Monitor
- CVE-2026-56814Plug: multipart :length limit is not charged for part headers, enabling unbounded temp-file creation (denial of service)27Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-56813Jul 10, 2026 · Cookie attribute injection in Plug.Conn.Cookies.encode/28Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| elixir-plug plug | 1.7.0 | Vendor (CNA) |
| elixir-plug plug_crypto | 2.2.1 | Vendor (CNA) |
| elixir-plug plug_crypto | 981887493dada0fce7003c61861c00dfbb0fc8c5 | Vendor (CNA) |
| Hex:plug | 1.7.0 | Package registry (OSV) |
| Hex:plug_crypto | 2.2.1 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayNov 13, 2026+21 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Neil Berkmanreporter
- Jonatan Männchen / EEFcoordinator
- José Valimremediation verifier
Not on record for this CVE: variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- Administrator privileges are required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-532 · Insertion of Sensitive Information into Log FileCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/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
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- SSVC exploitation— → none
- Exploit maturity— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (6 more)Show less
- github.com/elixir-plug/plug/commit/56000c33d8a0a2fbac491f8be06b9c5112bc2276
- github.com/elixir-plug/plug/commit/aeaa90e76b73ea90c3ecca9aae16fce71bd2a8d4
- github.com/elixir-plug/plug/security/advisories/GHSA-ffw9-w85g-f2vh
- github.com/elixir-plug/plug_crypto/commit/2d078b7b8264c565f0ff71235c515f4f46882dcf
- github.com/elixir-plug/plug_crypto/commit/981887493dada0fce7003c61861c00dfbb0fc8c5
- osv.dev/vulnerability/EEF-CVE-2026-105963
Vendor advisories and official records. Exploit/PoC links are deliberately left out.