CVE-2026-48862: Unbounded conn.streams growth in Mint HTTP/2 client via unenforced PUSH_PROMISE concurrency
Noroxi assessment
Priority: Monitor (action score 32/100)
- 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: 0.52% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: elixir-mint mint 1.9.0, 70b97b6a5209fb288b0e04d8e657dda26c59de67.
Low priority for now. Upgrade to elixir-mint mint 1.9.0, 70b97b6a5209fb288b0e04d8e657dda26c59de67 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
Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint Mint allows attacker-controlled HTTP/2 servers to exhaust memory in a Mint client via PUSH_PROMISE flooding. In lib/mint/http2.ex, Mint.HTTP2.decode_push_promise_headers_and_add_response/5 inserts a :reserved_remote entry into conn.streams for every promised stream ID. The neighbouring Mint.HTTP2.assert_valid_promised_stream_id/2 only verifies that the promised ID is even and not already present; client_settings.max_concurrent_streams is not consulted at promise time. The concurrency cap is only checked when the response HEADERS for the promised stream arrive, so a server that emits PUSH_PROMISE frames and withholds the matching HEADERS never trips that check. HTTP/2 server push is accepted by default (client_settings.enable_push defaults to true). A single long-lived HTTP/2 connection to a hostile server lets that server pin one conn.streams entry per PUSH_PROMISE frame it sends, with no upper bound, until the client process runs out of memory. This issue affects mint: from 0.2.0 before 1.9.0.
- Published
- Jun 2, 2026
- Updated
- Jul 22, 2026
- EPSS
- 0.5% · 43th percentile
- CWE
- CWE-770
Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 32 / 40 · 8.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · EEF
- 8.2
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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.
elixir-mint mint
- 0.2.0 and later · before 1.9.0affected · semver
- 65c6394d05a1b8aa4a7461708c3aa173e8d7a5cf and later · before 70b97b6a5209fb288b0e04d8e657dda26c59de67affected · git
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Hex | mint | from 0.2.0 · before 1.9.0 | 1.9.0 |
Same product
elixir-mint: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-56810mint buffers an entire chunked response chunk in memory in Mint.HTTP1.decode_body/534Monitor
- CVE-2026-91043HPACK-indexed cookie fields in Mint HTTP/2 responses bypass max_header_list_size and exhaust client memory32Monitor
- CVE-2026-82728Unbounded HTTP/1 status-line and chunk-extension buffering in Mint causes memory-exhaustion DoS32Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-48861Jun 2, 2026 · CRLF injection in HTTP/1 request line via unvalidated method in Mint8Monitor
- Later →CVE-2026-49753Jun 2, 2026 · HTTP response smuggling in Mint HTTP/1 client via lenient Content-Length parsing25Monitor
- Later →CVE-2026-49754Jun 2, 2026 · HTTP/2 CONTINUATION flood in Mint client via unbounded header-block accumulation32Monitor
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-mint mint | 1.9.0 | Vendor (CNA) |
| elixir-mint mint | 70b97b6a5209fb288b0e04d8e657dda26c59de67 | Vendor (CNA) |
| Hex:mint | 1.9.0 | 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.
- Eric Meadows-Jönssonremediation developer
- Peter Ullrichfinder
- Jonatan Männchen / EEFanalyst
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-5681034 days apartmint buffers an entire chunked response chunk in memory in Mint.HTTP1.decode_body/534Monitor
- CVE-2026-497540 days apartHTTP/2 CONTINUATION flood in Mint client via unbounded header-block accumulation32Monitor
- CVE-2026-5822942 days apartUnbounded HTTP/1 response-header and chunked-trailer accumulation in Mint causes memory-exhaustion DoS32Monitor
- CVE-2026-8272894 days apartUnbounded HTTP/1 status-line and chunk-extension buffering in Mint causes memory-exhaustion DoS32Monitor
- CVE-2026-91043118 days apartHPACK-indexed cookie fields in Mint HTTP/2 responses bypass max_header_list_size and exhaust client memory32Monitor
- CVE-2026-5924642 days apartZero-length HTTP/2 CONTINUATION frames bypass Mint's header-block byte-size cap and exhaust client memory25Monitor
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.
- No account or password is 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
- None
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-770 · Allocation of Resources Without Limits or ThrottlingCVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/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
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)
- FloodingCAPEC-125likelihood: High · Medium
- Excessive AllocationCAPEC-130likelihood: Medium · Medium
- XML Ping of the DeathCAPEC-147likelihood: Low · Medium
- Exponential Data ExpansionCAPEC-197likelihood: High · Medium
- Serialized Data Parameter BlowupCAPEC-229likelihood: High · High
- Serialized Data with Nested PayloadsCAPEC-230likelihood: Medium · High
- Oversized Serialized Data PayloadsCAPEC-231likelihood: Medium · High
- HTTP DoSCAPEC-469Low
ATT&CK techniques
- Network Denial of Service:Direct Network FloodT1498.001
- Network Denial of Service:Reflection AmplificationT1498.002
- Endpoint Denial of ServiceT1499
- Endpoint Denial of Service: OS Exhaustion FloodT1499.001
- Endpoint Denial of Service:Service Exhaustion FloodT1499.002
- Endpoint Denial of Service:Application Exhaustion FloodT1499.003
Change log
- Fix✗ → ✓
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References
Show all references (3 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.