How severe is CVE-2019-25025?

CVE-2019-25025 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2019-25025?

CVE-2019-25025 affects the following packages: activerecord-session_store (RubyGems). Ecosystems affected: RubyGems.

How do I fix CVE-2019-25025?

Update activerecord-session_store to 2.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-25025 is resolved across your whole dependency graph.

How do I detect CVE-2019-25025 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for activerecord-session_store, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2019-25025 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2019-25025 actively exploited in the wild?

No public exploit code has been indexed for CVE-2019-25025 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2019-25025?

CVE-2019-25025 has an EPSS (Exploit Prediction Scoring System) score of 1.8%, placing it in the 78th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2019-25025 published, and has it been updated?

CVE-2019-25025 was published on March 5, 2021 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎

💎 RubyGems

Not in CISA KEV

MEDIUM severity

CVE-2019-25025 — activerecord-session_store

MEDIUMFix: rails/activerecord-session_store#151

CVE-2019-25025 is a medium-severity (CVSS 5.3) vulnerability in activerecord-session_store. A fix is available for activerecord-session_store — see the affected versions and patch details below.

Activerecord-session_store Vulnerable to Timing Attack

Also known asGHSA-cvw2-xj8r-mjf7

Published

Mar 5, 2021

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs78th percentile — riskier than 78% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2019-25025 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

💎activerecord-session_store

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.

Description

The activerecord-session_store (aka Active Record Session Store) component through 1.1.3 for Ruby on Rails does not use a constant-time approach when delivering information about whether a guessed session ID is valid. Consequently, remote attackers can leverage timing discrepancies to achieve a correct guess in a relatively short amount of time. This is a related issue to CVE-2019-16782.

Recommendation

This has been fixed in version 2.0.0. All users are advised to update to this version or later.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`activerecord-session_store`	all versions	2.0.0`bundle update activerecord-session_store --conservative`

Affected Products

1 product · 1 configurations

Application

active record session storerubyonrails

≤ 1.1.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for activerecord-session_store, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update activerecord-session_store to 2.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-25025 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Product	Fixed in	Advisory
Red Hat Satellite 6.10 for RHEL 7	`tfm-rubygem-activerecord-session_store-0:2.0.0-1.el7sat`	RHSA-2021:4702

Frequently Asked Questions

The `activerecord-session_store` (aka Active Record Session Store) component through 1.1.3 for Ruby on Rails does not use a constant-time approach when delivering information about whether a guessed session ID is valid. Consequently, remote attackers can leverage timing discrepancies to achieve a correct guess in a relatively short amount of time. This is a related issue to CVE-2019-16782. ## Recommendation This has been fixed in version 2.0.0. All users are advised to update to this version or later.

O3 Security · Impact-Aware SCA

Is CVE-2019-25025 in your dependencies?

Find it across RubyGems, including transitive dependencies.

Scan my dependencies How O3 SCA works