Out of bounds read in bumpalo

published 2020-03-24 6 y ago modified 2026-06-17 4 mo ago also GHSA-vqx7-pw4r-29rr , RUSTSEC-2020-0006 , EUVD-2021-1902

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.5%; EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits: 0; none known

An issue was discovered in the bumpalo crate before 3.2.1 for Rust. The realloc feature allows the reading of unknown memory. Attackers can potentially read cryptographic keys.

Patch / fix

fixed in 2 distros 1 links 1

crates.io bumpalo 3.2.1
bumpalo_project bumpalo 3.2.1

rust-bumpalo Debian 14, Debian 13, Debian 12 3.2.1-1

debian advisories DEBIAN-CVE-2020-35861

rustsec.org/advisories/RUSTSEC-2020-0006.html advisory

Exploit prediction

1.51% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

rustsec.org https://rustsec.org/advisories/RUSTSEC-2020-0006.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:P/I:N/A:N
OSV	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
crates.io	bumpalo	>=3.0.0, <3.2.1	3.2.1

Classification

Weakness

CWE-125 Out-of-bounds Read

References

rustsec.org /advisories/RUSTSEC-2020-0006.html
web, exploit, patch, third-party-advisory, advisory
nvd.nist.gov /vuln/detail/CVE-2020-35861
advisory
github.com /fitzgen/bumpalo/issues/69
web, report
github.com /fitzgen/bumpalo
package
crates.io /crates/bumpalo
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary