- Exploited
- No known exploitation
- Fix
- Fixed in 1.1.6
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 1.1.6.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 10/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The extended-attribute functions in the rustix Rust crate's `rustix::fs` module mark bytes as initialized after a zero-length buffer call, even though the system call wrote nothing. Safe code that passes a full `Vec` through `spare_capacity` can use this to set the vector's length past its capacity, which causes undefined behavior.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
The extended-attribute functions in rustix::fs (getxattr, lgetxattr, fgetxattr, listxattr, llistxattr and flistxattr) write into a Buffer and then mark as many bytes initialized as the system call reported. When the buffer has zero length, the operating system treats the call as a size query: it writes nothing and returns the size of the attribute value or of the name list. rustix still marked that many bytes as initialized.
Passing a Vec whose length equals its capacity through spare_capacity gives such a zero-length buffer, and rustix then set the vector's length past its capacity over memory that was never written. This is undefined behavior reachable from safe code. With an empty &mut [MaybeUninit<u8>] the call panics instead.
From 1.1.6 these functions return an empty result for a zero-length buffer, and new getxattr_query, lgetxattr_query, fgetxattr_query, listxattr_query, llistxattr_query and flistxattr_query functions return the size. The 0.38 series did not have the Buffer API and is not affected.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure?/25Unknown. No advisory context yet
- Reach10/20Affects crates.io packages
- Severity?/10Unknown. No CVSS score or vendor rating
- No patch0/5No signal
What would change the score
- Would score about 65 if added to CISA KEV
- Would score about 60 if CISA's SSVC rates exploitation active
- Would score about 32 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 1.1.6.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by RUSTSEC-2026-0486 (xattr functions mark unwritten bytes as initialized when given a zero-length buffer), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for RUSTSEC-2026-0486 (entry last updated 2026-11-11):
Affected:
- crates.io package rustix: from 1.0.0, fixed in 1.1.6
Fixed versions: 1.1.6.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: RUSTSEC-2026-0486 is not listed as of cve.now's last read.
This KEV status is for RUSTSEC-2026-0486 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Packages (crates.io): find every lockfile in each project and run the stack.check operation of the cve.now MCP server (execute) on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://rustsec.org/advisories/RUSTSEC-2026-0486.html
- https://crates.io/crates/rustix
- https://github.com/bytecodealliance/rustix/commit/8e6aaa6713d2bb64b1fdd8c472e3a32a10a76d70
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/RUSTSEC-2026-0486
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "RUSTSEC-2026-0486"}.Timeline
- Advisory published15 days
- Record last updated
Affected versions
- rustixcrates.io
From 1.0.0 · fixed in 1.1.6
Evidence 3
Other links · 3
- Advisory
- Repository
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about RUSTSEC-2026-0486
Is RUSTSEC-2026-0486 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by RUSTSEC-2026-0486?
rustix (crates.io): from 1.0.0 before 1.1.6.Source: cve.now feed data
How do I fix RUSTSEC-2026-0486?
Upgrade to a fixed version: 1.1.6.Source: cve.now feed data