The (1) S_reghop3, (2) S_reghop4, and (3) S_reghopmaybe3 functions in regexec.c in Perl…
Priority LOW 38CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 fixed, 5 without a fix
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat.
Summary
The (1) S_reghop3, (2) S_reghop4, and (3) S_reghopmaybe3 functions in regexec.c in Perl before 5.24.0 allow context-dependent attackers to cause a denial of service (infinite loop) via crafted utf-8 data, as demonstrated by "a\x80."
Why it matters now
EPSS 0.02553 85th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 5 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:* | 22 | Vulnerable | Fedoraproject |
| cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:* | up to 5.23.9 | Vulnerable | Perl |
- cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:* Versions 22 Vulnerable ·Fedoraproject
- cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:* Versions up to 5.23.9 Vulnerable ·Perl
Remediation
Red Hat 1 advisory
- RHSA-2026:6206 Released 2026-03-30 · Red Hat rating ModerateRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images perl-5.42.2-524.hum1@aarch64, perl-5.42.2-524.hum1@src, perl-5.42.2-524.hum1@x86_64 +47
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Directory Server 8 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat Software Collections | Affected | No fix planned: Will not fix |
| Red Hat Hardened Images | Fixed | RHSA-2026:6206 |
Timeline
- 2026-10-02 Threatist record created from CVE-2015-8853
- 2026-10-03 Alias added: GHSA-c4jc-532j-fmvf
References
Advisory 5
Other 7
- [oss-security] 20160420 Re: CVE Request: perl: denial-of-service / Regexp-matching "hangs" indefinitely on illegal input using binmode :utf8 using 100%CPU
- [oss-security] 20160420 CVE Request: perl: denial-of-service / Regexp-matching "hangs" indefinitely on illegal input using binmode :utf8 using 100%CPU
- https://rt.perl.org/Public/Bug/Display.html?id=123562
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
- http://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html
- https://bugzilla.redhat.com/show_bug.cgi?id=1329106
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
Sources
- CVE-2015-8853 · CVE Program
- CVE-2015-8853 · NVD
- FIRST EPSS
- GHSA-c4jc-532j-fmvf · GitHub Advisory Database · CC BY 4.0
- CVE-2015-8853 · Red Hat security data · CC BY 4.0
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