CVE-2026-74994: inets, httpd: Authentication Bypass via Directory Namespace Collapse in httpd mod_auth
Noroxi assessment
Priority: Monitor (action score 24/100)
- 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: 0.63% (FIRST EPSS); higher than 50.5% of all records.
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Erlang OTP 27.3.4.17, 28.5.0.6, 29.0.6; azl3 erlang 26.2.5.21-4 on Azure Linux 3.0 26.2.5.21-6; azl3 erlang 26.2.5.21-6 on Azure Linux 3.0 26.2.5.21-6.
Low priority for now. Upgrade to Erlang OTP 27.3.4.17, 28.5.0.6, 29.0.6; azl3 erlang 26.2.5.21-4 on Azure Linux 3.0 26.2.5.21-6; azl3 erlang 26.2.5.21-6 on Azure Linux 3.0 26.2.5.21-6 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
The mod_auth module in OTP's inets httpd server, when configured with dets or mnesia authentication backends and multiple directory configuration blocks, collapses all directory blocks into a single shared user/group namespace. A user added to one protected directory is accepted as valid for all other protected directories on the same server instance. This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.
- Published
- Sep 1, 2026
- Updated
- Sep 8, 2026
- EPSS
- 0.6% · 50th percentile
- CWE
- CWE-863
Report tools
Action score
24
Monitor
Low priority for now.
- CVSS
- 24 / 40 · 6.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.6%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · EEF
- 6.0
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/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.
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Noroxi 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.
Erlang OTP
- before 17.0unknown · otp
- 17.0 and later · before 27.3.4.17affected · otp
- 28.0 and later · before 28.5.0.6affected · otp
- 29.0 and later · before 29.0.6affected · otp
- before 5.10unknown · otp
- 5.10 and later · before 9.3.2.7affected · otp
- 9.4 and later · before 9.6.2.3affected · otp
- 9.7 and later · before 9.7.2affected · otp
- 84adefa331c4159d432d22840663c38f155cd4c1 and lateraffected · gitfixed in 6982e381137ede21a4e1faf5fa2dd82321691176, c5ccec8ed25c70ec6557fd81277e4b2f52285c19, 6101cb74ff2870718c622ba7af0c100f7f2524e3
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | erlang | from 0 | — |
| Debian:13 | erlang | before 1:27.3.4.1+dfsg-1+deb13u4 | 1:27.3.4.1+dfsg-1+deb13u4 |
| Debian:14 | erlang | before 1:29.0.6+dfsg-1 | 1:29.0.6+dfsg-1 |
| Red Hat:hummingbird:1 | erlang27 | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-asn1 | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-common_test | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-compiler | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-crypto | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-debugger | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-dialyzer | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-diameter | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-edoc | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-eldap | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-erl_interface | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-erts | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-et | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-eunit | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-examples | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-ftp | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-gdb-tools | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-inets | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-jinterface | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-kernel | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
| Red Hat:hummingbird:1 | erlang27-megaco | before 0:27.3.4.17-0.1.hum1 | 0:27.3.4.17-0.1.hum1 |
+18
Same product
erlang: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-89422TLS 1.3 client skips server authentication when ServerHello carries an unsolicited pre_shared_key extension37Monitor
- CVE-2026-74835inets,httpd: Memory Exhaustion via Unenforced max_body_size During Chunked Body Reception34Monitor
- CVE-2026-71380httpd applies no timeout while receiving a request body, parking a worker on a stalled client34Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-73276Sep 1, 2026 · inets, httpd: HTTP Request Smuggling via Whitespace-Before-Colon Header Dropping i33Monitor
- ← EarlierCVE-2026-73812Sep 1, 2026 · inets, httpd: HTTP Request Smuggling via Transfer-Encoding and Content-Length33Monitor
- Later →CVE-2026-75538Sep 1, 2026 · A Signed Length Overflow in Erlang/OTP's inet TCP Driver Overflows the Receive Buffer Into BEAM VM Memory From an Unauthenticated Peer32Monitor
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 |
|---|---|---|
| Erlang OTP | 27.3.4.17 | Vendor (CNA) |
| Erlang OTP | 28.5.0.6 | Vendor (CNA) |
| Erlang OTP | 29.0.6 | Vendor (CNA) |
| Erlang OTP | 6101cb74ff2870718c622ba7af0c100f7f2524e3 | Vendor (CNA) |
| Erlang OTP | 6982e381137ede21a4e1faf5fa2dd82321691176 | Vendor (CNA) |
| Erlang OTP | 9.3.2.7 | Vendor (CNA) |
| Erlang OTP | 9.6.2.3 | Vendor (CNA) |
| Erlang OTP | 9.7.2 | Vendor (CNA) |
| Erlang OTP | c5ccec8ed25c70ec6557fd81277e4b2f52285c19 | Vendor (CNA) |
| azl3 erlang 26.2.5.21-4 on Azure Linux 3.0 | 26.2.5.21-6 | Microsoft (MSRC) |
| azl3 erlang 26.2.5.21-6 on Azure Linux 3.0 | 26.2.5.21-6 | Microsoft (MSRC) |
| debian:erlang | 1:27.3.4.1+dfsg-1+deb13u4 · Debian:13 | Package registry (OSV) |
| debian:erlang | 1:29.0.6+dfsg-1 · Debian:14 | Package registry (OSV) |
| red hat:erlang27 | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-asn1 | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-common_test | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-compiler | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-crypto | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-debugger | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-dialyzer | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-diameter | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-edoc | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-eldap | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-erl_interface | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:erlang27-erts | 0:27.3.4.17-0.1.hum1 · Red Hat:hummingbird: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.
No dated events beyond publication.
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.
- Konrad Pietrzakremediation developer
- Lukas Backström / Erlang Solutionsfinder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- 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
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-863 · Incorrect AuthorizationCVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
- github.com/erlang/otp/commit/6101cb74ff2870718c622ba7af0c100f7f2524e3
- github.com/erlang/otp/commit/6982e381137ede21a4e1faf5fa2dd82321691176
- github.com/erlang/otp/commit/c5ccec8ed25c70ec6557fd81277e4b2f52285c19
- github.com/erlang/otp/security/advisories/GHSA-c3cq-q8x6-547g
- osv.dev/vulnerability/EEF-CVE-2026-74994
Vendor advisories and official records. Exploit/PoC links are deliberately left out.