CVE-2017-7526

libgcrypt before version 1.7.8 is vulnerable to a cache side-channel attack resulting into a complete break of RSA-1024 while using the left-to-right method for computing the sliding-window expansion. The same attack is believed to work on RSA-2048 with moderately more computation. This side-channel requires that attacker can run arbitrary software on the hardware where the private RSA key is used.

Published: 2018-07-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-7526 is rated Moderate Risk (54.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.77%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2017-7526

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-24 2.57% 2.77% +0.20%
2 2026-02-09 2.70% 2.57% -0.13%
3 2026-01-19 — 2.70% —

Full EPSS history (39 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-7526

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.6 4.0 [email protected]
6.8 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 4.0 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2017-7526

OS Trackers for CVE-2017-7526

vendor priority summary link
alpine — CVE-2017-7526: 1 source package rows (gnupg1); 4 state rows across 4 repos (3.10-main, 3.11-main, 3.12-main, edge-community); fixed 4, open 0. https://security.alpinelinux.org/vuln/CVE-2017-7526
debian unimportant CVE-2017-7526 unimportant priority: Debian including 3 source packages (gnupg1, gnupg2, libgcrypt20), 15 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 15. https://security-tracker.debian.org/tracker/CVE-2017-7526
redhat medium — https://access.redhat.com/security/cve/CVE-2017-7526
suse low CVE-2017-7526 severity low: SUSE including 321 source package names (0.9.1:libgcrypt20-1.6.1-16.42.1, 1.0.0:libgcrypt20-1.6.1-16.42.1, …), 387 product×package rows across 80 product lines (Container caasp/v4/default-http-backend, Container caasp/v4/dnsmasq-nanny, … (80 product lines)): Fixed 230, Known Affected 157. https://www.suse.com/security/cve/CVE-2017-7526/
ubuntu medium CVE-2017-7526 medium priority: Ubuntu including 4 source packages (gnupg, gnupg1, libgcrypt11, libgcrypt20), 30 status rows across 9 suites (artful, bionic, cosmic, disco, trusty, upstream, xenial, yakkety, zesty): DNE 13, not-affected 7, released 7, needs-triage 3. https://ubuntu.com/security/CVE-2017-7526

Affected software / configurations for CVE-2017-7526

Vendor Product Version Raw CPE
gnupg libgcrypt < 1.7.8 cpe:2.3:a:gnupg:libgcrypt:*:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2017-7526

URL Tags
http://www.securityfocus.com/bid/99338 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1038915 Third Party Advisory VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-7526 Issue Tracking Patch Third Party Advisory
https://eprint.iacr.org/2017/627 Third Party Advisory
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=78130828e9a140a9de4dafadbc844dbb64cb709a
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=8725c99ffa41778f382ca97233183bcd687bb0ce
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=e6a3dc9900433bbc8ad362a595a3837318c28fa9
https://lists.gnupg.org/pipermail/gnupg-announce/2017q2/000408.html Mailing List Vendor Advisory
https://usn.ubuntu.com/3733-1/ Third Party Advisory
https://usn.ubuntu.com/3733-2/ Third Party Advisory
https://www.debian.org/security/2017/dsa-3901 Third Party Advisory
https://www.debian.org/security/2017/dsa-3960 Third Party Advisory
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