CVE-2026-34353: In OCaml through 4.14.3, Bigarray.reshape allows an integer overflow, and resultant reading of arbitrary memory, when untrusted data is proc
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: 0.11% (FIRST EPSS).
- Someone with local access to the system can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: azl3 ocaml 5.1.1-1 on Azure Linux 3.0 5.1.1-2; azl3 ocaml 5.1.1-2 on Azure Linux 3.0 5.1.1-2; cbl2 ocaml 4.13.1-2 on CBL Mariner 2.0 4.13.1-3.
Low priority for now. Upgrade to azl3 ocaml 5.1.1-1 on Azure Linux 3.0 5.1.1-2; azl3 ocaml 5.1.1-2 on Azure Linux 3.0 5.1.1-2; cbl2 ocaml 4.13.1-2 on CBL Mariner 2.0 4.13.1-3 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
In OCaml through 4.14.3, Bigarray.reshape allows an integer overflow, and resultant reading of arbitrary memory, when untrusted data is processed.
- Published
- Mar 27, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.1% · 1th percentile
- CWE
- CWE-190
Report tools
Action score
20
Monitor
Low priority for now.
- CVSS
- 20 / 40 · 5.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.1
- CNA · mitre
- 5.9
- 0.8 point gap
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A: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.
| Vendor | Product | CPE |
|---|---|---|
| ocaml | ocaml | cpe:2.3:a:ocaml:ocaml |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- ocaml ocamlup to 4.14.3 inclusive
Versions reported by the vendor
Affected version ranges reported by the assigning authority (mitre). Independent of NVD's CPE analysis and usually ahead of it.
OCaml OCaml
- up to and including 4.14.3affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | ocaml | from 0 | — |
| Debian:13 | ocaml | before 5.2.0-1 | 5.2.0-1 |
| openSUSE:Tumbleweed | ocaml | before 4.14.4-1.1 | 4.14.4-1.1 |
Same product
ocaml: all recordsOther highest-scoring records for the same primary product.
- CVE-2018-9838The caml_ba_deserialize function in byterun/bigarray.c in the standard library in OCaml 4.06.0 has an integer overflow which, in situations 40Plan
- CVE-2017-9772Insufficient sanitisation in the OCaml compiler versions 4.04.0 and 4.04.1 allows external code to be executed with raised privilege in bina40Plan
- CVE-2015-8869OCaml before 4.03.0 does not properly handle sign extensions, which allows remote attackers to conduct buffer overflow attacks or obtain sen38Monitor
Published before and after this one in the same product
- ← EarlierCVE-2017-9779Sep 7, 2017 · OCaml compiler allows attackers to have unspecified impact via unknown vectors, a similar issue to CVE-2017-9772 "but with much less impact.31Monitor
- ← EarlierCVE-2026-28364Feb 27, 2026 · In OCaml before 4.14.3 and 5.x before 5.4.1, a buffer over-read in Marshal deserialization (runtime/intern.c) enables remote code execution 31Monitor
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 |
|---|---|---|
| azl3 ocaml 5.1.1-1 on Azure Linux 3.0 | 5.1.1-2 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 ocaml 5.1.1-2 on Azure Linux 3.0 | 5.1.1-2 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 ocaml 4.13.1-2 on CBL Mariner 2.0 | 4.13.1-3 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 ocaml 4.13.1-3 on CBL Mariner 2.0 | 4.13.1-3 · CBL-Mariner Releases | Microsoft (MSRC) |
| debian:ocaml | 5.2.0-1 · Debian:13 | Package registry (OSV) |
| opensuse:ocaml | 4.14.4-1.1 · openSUSE:Tumbleweed | 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.
No history yet (it accumulates with the daily EPSS job).
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.
No credits in the CNA record.
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
- Someone with local access to the system can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Local
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-190 · Integer Overflow or WraparoundCVSS vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd-primary
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
- Fix✗ → ✓
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References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.